wip(plugins): save selected-terminal sharing authority and contract

# Conflicts:
#	electron/plugins/hostService.cjs
#	packages/plugin-cli/src/manifest.ts
#	packages/plugin-contract/src/index.ts
#	packages/plugin-sdk/src/index.ts

application/app/AppView.tsx

@@ -167,7 +167,8 @@ function AppPluginKeybindingThemeHost({
   sessions: any[];
   workspaces: any[];
 }) {
-  const appThemeStyle = useAppThemeStyle();
+  // View environment is global in the current host: publish committed colors only.
+  const appThemeStyle = useAppThemeStyle(false);
   const { resolvedTheme, uiLanguage } = useSettingsChromeStore();
   const pluginThemeTokens = useMemo(
     () => selectPluginThemeTokens(appThemeStyle as Record<string, unknown>),

application/app/useAppThemeStyle.ts

@@ -1,3 +1,4 @@
+import { usePluginThemeRevision } from '../state/usePluginThemeRuntime';
 import type React from 'react';
 import { useMemo } from 'react';
 
@@ -12,17 +13,20 @@ import { getUiThemeById } from '../../infrastructure/config/uiThemes';
  * settingsChromeStore so accent drags only re-render the leaf that applies the
  * vars, never the App shell.
  */
-export function useAppThemeStyle(): React.CSSProperties {
+export function useAppThemeStyle(includePreview = true): React.CSSProperties {
+  const pluginThemeRevision = usePluginThemeRevision();
   const { accentMode, customAccent } = useAppearanceChromeStore();
   const { resolvedTheme, darkUiThemeId, lightUiThemeId } = useSettingsChromeStore();
   return useMemo(() => {
+    void pluginThemeRevision; // getUiThemeById reads this external registry revision.
     const tokens = getUiThemeById(
       resolvedTheme,
       resolvedTheme === 'dark' ? darkUiThemeId : lightUiThemeId,
+      includePreview,
     ).tokens;
     return {
       ...buildAppThemeCssVars(tokens, accentMode, customAccent),
       colorScheme: resolvedTheme,
     } as React.CSSProperties;
-  }, [accentMode, customAccent, darkUiThemeId, lightUiThemeId, resolvedTheme]);
+  }, [accentMode, customAccent, darkUiThemeId, lightUiThemeId, resolvedTheme, pluginThemeRevision, includePreview]);
 }

application/i18n/locales/en/core.ts

@@ -1246,6 +1246,12 @@ Highlight the focused split pane:
   "settings.plugins.manager.remove": "Uninstall",
   "settings.plugins.manager.removeNote": "Uninstall removes package code and local KV data. User-owned settings, secrets and sync sidecars are retained.",
   "settings.plugins.permissions.statusUnknown": "Status unknown",
+  "plugins.sidebar.extensions": "Extension pages",
+  "plugins.sidebar.selectTerminal": "Select an open terminal first.",
+  "plugins.sidebar.loading": "Loading extension page…",
+  "plugins.vault.loading": "Loading plugin page…",
+  "plugins.vault.extensions": "Extensions",
+  "plugins.vault.back": "Back to hosts",
   "plugins.interaction.title": "Plugin request",
   "plugins.interaction.sharing": "Text you share becomes available to this plugin and its granted capabilities, including network access. Reading does not approve a new network destination.",
   "plugins.interaction.input": "Input text",
@@ -1274,6 +1280,19 @@ Highlight the focused split pane:
   "settings.plugins.manager.noPermissions": "No privileged permissions declared.",
   "settings.plugins.manager.required": "Required",
   "settings.plugins.manager.optional": "Optional",
+  "settings.plugins.themes.title": "Plugin themes",
+  "settings.plugins.themes.description": "Preview changes only this window. Apply saves this device’s selection. Personal accent, fonts and terminal overrides stay in control.",
+  "settings.plugins.themes.empty": "No enabled plugin themes for this mode.",
+  "settings.plugins.themes.choose": "Choose a theme",
+  "settings.plugins.themes.unavailable": "Saved theme unavailable; using the host default",
+  "settings.plugins.themes.applied": "Applied",
+  "settings.plugins.themes.preview": "Preview",
+  "settings.plugins.themes.apply": "Apply",
+  "settings.plugins.themes.cancel": "Cancel preview",
+  "settings.plugins.themes.restore": "Restore default",
+  "settings.plugins.themes.invalid": "Some theme palettes were rejected or unavailable.",
+  "settings.plugins.themes.failed": "Could not apply theme.",
+  "settings.plugins.manager.dataTheme": "Theme pack: validated colors, no executable runtime.",
   "settings.plugins.manager.browser": "Browser runtime: privileged access goes through host permission brokers.",
   "settings.plugins.manager.advanced": "Advanced runtime: full Node filesystem and network authority. Broker permissions cannot restrict this access. Development preview only.",
   "settings.plugins.manager.data": "Local KV stays on this device. Only non-secret settings explicitly marked for sync participate in encrypted cloud sidecars. Packages and permission grants do not sync.",

application/i18n/locales/es/core.ts

@@ -1246,6 +1246,12 @@ Resalta el panel dividido enfocado:
   "settings.plugins.manager.remove": "Desinstalar",
   "settings.plugins.manager.removeNote": "La desinstalación elimina el código y los datos KV locales. Se conservan los ajustes del usuario, los secretos y los datos auxiliares de sincronización.",
   "settings.plugins.permissions.statusUnknown": "Estado desconocido",
+  "plugins.sidebar.extensions": "Páginas de extensiones",
+  "plugins.sidebar.selectTerminal": "Selecciona primero un terminal abierto.",
+  "plugins.sidebar.loading": "Cargando página de extensión…",
+  "plugins.vault.loading": "Cargando página del plugin…",
+  "plugins.vault.extensions": "Extensiones",
+  "plugins.vault.back": "Volver a hosts",
   "plugins.interaction.title": "Solicitud de complemento",
   "plugins.interaction.sharing": "El texto compartido estará disponible para este complemento y sus capacidades autorizadas, incluida la red. Leer no autoriza un nuevo destino de red.",
   "plugins.interaction.input": "Introducir texto",
@@ -1274,6 +1280,19 @@ Resalta el panel dividido enfocado:
   "settings.plugins.manager.noPermissions": "No se han declarado permisos privilegiados.",
   "settings.plugins.manager.required": "Obligatorio",
   "settings.plugins.manager.optional": "Opcional",
+  "settings.plugins.themes.title": "Temas de plugins",
+  "settings.plugins.themes.description": "La vista previa solo cambia esta ventana. Aplicar guarda la selección en este dispositivo. Se conservan los ajustes personales.",
+  "settings.plugins.themes.empty": "No hay temas habilitados para este modo.",
+  "settings.plugins.themes.choose": "Elegir tema",
+  "settings.plugins.themes.unavailable": "Tema guardado no disponible; se usa el predeterminado",
+  "settings.plugins.themes.applied": "Aplicado",
+  "settings.plugins.themes.preview": "Vista previa",
+  "settings.plugins.themes.apply": "Aplicar",
+  "settings.plugins.themes.cancel": "Cancelar vista previa",
+  "settings.plugins.themes.restore": "Restaurar predeterminado",
+  "settings.plugins.themes.invalid": "Algunas paletas no están disponibles o no son válidas.",
+  "settings.plugins.themes.failed": "No se pudo aplicar el tema.",
+  "settings.plugins.manager.dataTheme": "Paquete de temas: colores validados, sin ejecución de código.",
   "settings.plugins.manager.browser": "Entorno de navegador: el acceso privilegiado pasa por los controles de permisos del anfitrión.",
   "settings.plugins.manager.advanced": "Entorno avanzado: acceso completo de Node al sistema de archivos y a la red. Los permisos del intermediario no restringen este acceso. Solo para desarrollo.",
   "settings.plugins.manager.data": "Los datos KV permanecen en este dispositivo. Solo los ajustes no secretos marcados para sincronización participan en los datos auxiliares cifrados. Los paquetes y las autorizaciones no se sincronizan.",

application/i18n/locales/ru/core.ts

@@ -1141,6 +1141,12 @@ export const ruCoreMessages: Messages = {
   "settings.plugins.manager.remove": "Удалить",
   "settings.plugins.manager.removeNote": "Удаление очищает код пакета и локальные данные KV. Настройки пользователя, секреты и данные синхронизации сохраняются.",
   "settings.plugins.permissions.statusUnknown": "Состояние неизвестно",
+  "plugins.sidebar.extensions": "Страницы расширений",
+  "plugins.sidebar.selectTerminal": "Сначала выберите открытый терминал.",
+  "plugins.sidebar.loading": "Загрузка страницы расширения…",
+  "plugins.vault.loading": "Загрузка страницы плагина…",
+  "plugins.vault.extensions": "Расширения",
+  "plugins.vault.back": "К хостам",
   "plugins.interaction.title": "Запрос плагина",
   "plugins.interaction.sharing": "Переданный текст доступен плагину и его разрешённым возможностям, включая сеть. Чтение не разрешает новый сетевой адрес.",
   "plugins.interaction.input": "Ввести текст",
@@ -1169,6 +1175,19 @@ export const ruCoreMessages: Messages = {
   "settings.plugins.manager.noPermissions": "Привилегированные разрешения не заявлены.",
   "settings.plugins.manager.required": "Обязательно",
   "settings.plugins.manager.optional": "Необязательно",
+  "settings.plugins.themes.title": "Темы плагинов",
+  "settings.plugins.themes.description": "Предпросмотр меняет только это окно. Применение сохраняет выбор на этом устройстве. Личные настройки сохраняются.",
+  "settings.plugins.themes.empty": "Нет включённых тем для этого режима.",
+  "settings.plugins.themes.choose": "Выберите тему",
+  "settings.plugins.themes.unavailable": "Сохранённая тема недоступна; используется стандартная палитра",
+  "settings.plugins.themes.applied": "Применено",
+  "settings.plugins.themes.preview": "Предпросмотр",
+  "settings.plugins.themes.apply": "Применить",
+  "settings.plugins.themes.cancel": "Отменить предпросмотр",
+  "settings.plugins.themes.restore": "Сбросить тему",
+  "settings.plugins.themes.invalid": "Некоторые палитры недоступны или отклонены.",
+  "settings.plugins.themes.failed": "Не удалось применить тему.",
+  "settings.plugins.manager.dataTheme": "Пакет тем: проверенные цвета без выполнения кода.",
   "settings.plugins.manager.browser": "Браузерная среда: привилегированный доступ проходит через проверку разрешений приложения.",
   "settings.plugins.manager.advanced": "Расширенная среда: полный доступ Node к файловой системе и сети. Разрешения посредника не ограничивают этот доступ. Только для разработки.",
   "settings.plugins.manager.data": "Данные KV остаются на устройстве. Синхронизируются только явно отмеченные несекретные настройки в зашифрованных данных. Пакеты и разрешения не синхронизируются.",

application/i18n/locales/zh-CN/core.ts

@@ -1161,6 +1161,12 @@ Vaults 标签保持扁平，不使用这块背景。
   "settings.plugins.manager.remove": "卸载",
   "settings.plugins.manager.removeNote": "卸载会移除插件代码和本地 KV 数据，保留用户设置、秘密存储和同步 sidecar。",
   "settings.plugins.permissions.statusUnknown": "状态未知",
+  "plugins.sidebar.extensions": "扩展页面",
+  "plugins.sidebar.selectTerminal": "请先选择已打开的终端。",
+  "plugins.sidebar.loading": "正在加载扩展页面…",
+  "plugins.vault.loading": "正在加载插件页面…",
+  "plugins.vault.extensions": "扩展",
+  "plugins.vault.back": "返回主机",
   "plugins.interaction.title": "插件请求",
   "plugins.interaction.sharing": "分享的文本将交给此插件及其已授权的能力（包括网络访问）。读取文本不代表批准新的网络目标。",
   "plugins.interaction.input": "输入文本",
@@ -1189,6 +1195,19 @@ Vaults 标签保持扁平，不使用这块背景。
   "settings.plugins.manager.noPermissions": "未声明特权权限。",
   "settings.plugins.manager.required": "必需",
   "settings.plugins.manager.optional": "可选",
+  "settings.plugins.themes.title": "插件主题",
+  "settings.plugins.themes.description": "预览仅影响当前窗口；应用后保存在本设备。个人强调色、字体和终端覆盖设置仍然优先。",
+  "settings.plugins.themes.empty": "当前模式没有已启用的插件主题。",
+  "settings.plugins.themes.choose": "选择主题",
+  "settings.plugins.themes.unavailable": "已保存的主题不可用，正在使用宿主默认配色",
+  "settings.plugins.themes.applied": "已应用",
+  "settings.plugins.themes.preview": "预览",
+  "settings.plugins.themes.apply": "应用",
+  "settings.plugins.themes.cancel": "取消预览",
+  "settings.plugins.themes.restore": "恢复默认",
+  "settings.plugins.themes.invalid": "部分主题配色未通过验证或不可用。",
+  "settings.plugins.themes.failed": "无法应用主题。",
+  "settings.plugins.manager.dataTheme": "主题包：已验证配色，不启动代码运行时。",
   "settings.plugins.manager.browser": "浏览器运行时：特权访问通过宿主权限代理。",
   "settings.plugins.manager.advanced": "高级运行时：拥有完整 Node 文件系统和网络能力，代理权限无法限制这些访问。仅供开发预览。",
   "settings.plugins.manager.data": "本地 KV 仅保留在此设备。只有明确标记为同步的非秘密设置进入加密云 sidecar。插件包和权限授权不参与同步。",

application/i18n/locales/zh-TW/core.ts

@@ -1164,6 +1164,12 @@ Vaults 分頁維持扁平，不使用這塊背景。
   "settings.plugins.manager.remove": "卸載",
   "settings.plugins.manager.removeNote": "卸載會移除插件代碼和本地 KV 數據，保留用戶設置、秘密存儲和同步 sidecar。",
   "settings.plugins.permissions.statusUnknown": "狀態不明",
+  "plugins.sidebar.extensions": "擴充功能頁面",
+  "plugins.sidebar.selectTerminal": "請先選擇已開啟的終端。",
+  "plugins.sidebar.loading": "正在載入擴充功能頁面…",
+  "plugins.vault.loading": "正在載入擴充功能頁面…",
+  "plugins.vault.extensions": "擴充功能",
+  "plugins.vault.back": "返回主機",
   "plugins.interaction.title": "外掛請求",
   "plugins.interaction.sharing": "分享的文字會交給此外掛及其已授權能力（包括網路存取）。讀取文字不代表核准新的網路目的地。",
   "plugins.interaction.input": "輸入文字",
@@ -1192,6 +1198,19 @@ Vaults 分頁維持扁平，不使用這塊背景。
   "settings.plugins.manager.noPermissions": "未聲明特權權限。",
   "settings.plugins.manager.required": "必需",
   "settings.plugins.manager.optional": "可選",
+  "settings.plugins.themes.title": "外掛主題",
+  "settings.plugins.themes.description": "預覽僅影響目前視窗；套用後儲存於本機。個人強調色、字型和終端覆寫設定仍然優先。",
+  "settings.plugins.themes.empty": "目前模式沒有已啟用的外掛主題。",
+  "settings.plugins.themes.choose": "選擇主題",
+  "settings.plugins.themes.unavailable": "已儲存的主題無法使用，正在使用宿主預設配色",
+  "settings.plugins.themes.applied": "已套用",
+  "settings.plugins.themes.preview": "預覽",
+  "settings.plugins.themes.apply": "套用",
+  "settings.plugins.themes.cancel": "取消預覽",
+  "settings.plugins.themes.restore": "恢復預設",
+  "settings.plugins.themes.invalid": "部分主題配色未通過驗證或無法使用。",
+  "settings.plugins.themes.failed": "無法套用主題。",
+  "settings.plugins.manager.dataTheme": "主題套件：已驗證配色，不啟動程式執行環境。",
   "settings.plugins.manager.browser": "瀏覽器運行時：特權訪問通過宿主權限代理。",
   "settings.plugins.manager.advanced": "高級運行時：擁有完整 Node 文件系統和網絡能力，代理權限無法限制這些訪問。僅供開發預覽。",
   "settings.plugins.manager.data": "本地 KV 僅保留在此設備。只有明確標記為同步的非秘密設置進入加密雲 sidecar。插件包和權限授權不參與同步。",

application/state/pluginVaultPages.ts

@@ -0,0 +1,27 @@
+export const PLUGIN_VAULT_PAGE_PREFIX = 'plugin-vault:';
+
+export interface PluginVaultPage {
+  key: `plugin-vault:${string}`;
+  pluginId: string;
+  pluginName: string;
+  version: string;
+  viewId: string;
+  title: string;
+  icon?: NetcattyPluginIconReference;
+  order: number;
+}
+
+export function collectPluginVaultPages(plugins: NetcattyPluginContributionSnapshot['plugins']): PluginVaultPage[] {
+  return plugins.flatMap((plugin) => plugin.views
+    .filter((view) => view.location === 'vault-page' && view.visible)
+    .map((view): PluginVaultPage => ({
+      key: `${PLUGIN_VAULT_PAGE_PREFIX}${view.id}`,
+      pluginId: plugin.id, pluginName: plugin.displayName, version: plugin.version,
+      viewId: view.id, title: view.title, icon: view.icon, order: view.order ?? 0,
+    })))
+    .sort((left, right) => left.order - right.order || left.viewId.localeCompare(right.viewId));
+}
+
+export function resolvePluginVaultPage(pages: readonly PluginVaultPage[], section: string): PluginVaultPage | null {
+  return pages.find((page) => page.key === section) ?? null;
+}

application/state/pluginViewOcclusion.ts

@@ -0,0 +1,18 @@
+/** Native child views must yield to host dialogs and overlapping portals. */
+export function isPluginViewOccluded(mount: HTMLElement): boolean {
+  const rect = mount.getBoundingClientRect();
+  if (!mount.isConnected || mount.closest('[hidden], [inert], [aria-hidden="true"]')) return true;
+  const overlays = mount.ownerDocument.querySelectorAll(
+    '[data-app-lock-overlay], [role="dialog"], [role="alertdialog"], '
+    + '[role="menu"][data-state="open"], [data-radix-popper-content-wrapper] > *, [data-native-view-occluder]',
+  );
+  return [...overlays].some((overlay) => {
+    if (mount.contains(overlay)) return false;
+    const style = getComputedStyle(overlay);
+    if (style.display === 'none' || style.visibility === 'hidden' || overlay.closest('[hidden], [inert]')) return false;
+    if (overlay.matches('[data-app-lock-overlay], [role="dialog"][aria-modal="true"], [role="alertdialog"]')) return true;
+    const other = overlay.getBoundingClientRect();
+    return other.width > 0 && other.height > 0 && other.x < rect.right && other.right > rect.x
+      && other.y < rect.bottom && other.bottom > rect.y;
+  });
+}

application/state/settingsStateDefaults.ts

@@ -1,3 +1,4 @@
+import { pluginThemeRegistry } from '../../infrastructure/config/pluginThemeRegistry';
 import {
   DEFAULT_SHIFT_ENTER_NEWLINE_TEXT,
   isLegacyDefaultShiftEnterNewlineText,
@@ -252,6 +253,9 @@ export const applyThemeTokens = (
   accentOverride: string,
 ) => {
   const root = window.document.documentElement;
+  root.toggleAttribute('data-plugin-theme-active', pluginThemeRegistry.isActive(resolvedTheme));
+  const securityVars = buildAppThemeCssVars(pluginThemeRegistry.securityTokens(resolvedTheme), 'theme', '');
+  for (const [key, value] of Object.entries(securityVars)) root.style.setProperty('--host-security' + key.slice(1), value);
   root.classList.remove('light', 'dark');
   root.classList.add(resolvedTheme);
   const cssVars = buildAppThemeCssVars(tokens, accentMode, accentOverride);

application/state/terminalSidePanelTabs.ts

@@ -13,11 +13,11 @@ import {
 } from '../../infrastructure/config/storageKeys';
 import { localStorageAdapter } from '../../infrastructure/persistence/localStorageAdapter';
 import { useToolbarItemLayout } from './useToolbarItemLayout';
-import type { SidePanelTool } from '../../domain/sidePanelLayout';
+import type { BuiltinSidePanelTool, SidePanelTool } from '../../domain/sidePanelLayout';
 
 export type TerminalSidePanelTabId = SidePanelTool;
 
-export const TERMINAL_SIDE_PANEL_TAB_DEFAULT_ORDER: TerminalSidePanelTabId[] = [
+export const TERMINAL_SIDE_PANEL_TAB_DEFAULT_ORDER: BuiltinSidePanelTool[] = [
   'sftp',
   'browser',
   'scripts',

application/state/useActiveChromeTheme.ts

@@ -1,3 +1,6 @@
+import { pluginThemeRegistry } from '../../infrastructure/config/pluginThemeRegistry';
+import { usePluginThemeRevision } from './usePluginThemeRuntime';
+import { useSettingsChromeStore } from './settingsChromeStore';
 import { useLayoutEffect, useRef } from "react";
 import type { TerminalTheme } from "../../domain/models";
 import {
@@ -271,12 +274,15 @@ export function useActiveChromeTheme({
   activeTheme: TerminalTheme | null;
   applyAppTheme: () => void;
 }) {
+  const pluginThemeRevision = usePluginThemeRevision();
+  const { resolvedTheme } = useSettingsChromeStore();
+  const effectiveTheme = pluginThemeRegistry.isActive(resolvedTheme) ? null : activeTheme;
   const applyAppThemeRef = useRef(applyAppTheme);
   applyAppThemeRef.current = applyAppTheme;
 
   useLayoutEffect(() => {
-    syncActiveChromeTheme(activeTheme, applyAppTheme);
-  }, [activeTheme, applyAppTheme]);
+    syncActiveChromeTheme(effectiveTheme, applyAppTheme);
+  }, [effectiveTheme, applyAppTheme, pluginThemeRevision]);
 
   useLayoutEffect(() => {
     return () => {

application/state/useEmbeddedPluginView.ts

@@ -0,0 +1,119 @@
+import { useEffect, useRef, useState } from 'react';
+import { PluginViewLifecycleController, type HostedPluginViewState } from './pluginViewLifecycle';
+import { resolvePluginViewWindowScope } from './pluginViewScopes';
+import { isPluginViewOccluded } from './pluginViewOcclusion';
+import type { UsePluginContributionsResult } from './usePluginContributions';
+
+type ViewAdapter = Pick<UsePluginContributionsResult, 'openView' | 'closeView' | 'focusView' | 'setViewBounds' | 'setViewVisibility' | 'onViewClosed' | 'onViewFocused'>;
+
+/** Host-owned mounting only. No plugin router, DOM, session or vault data API. */
+export function useEmbeddedPluginView({ viewId, version, slot, active, context, adapter, subscribeHidden, unavailable, focused, focusOnReveal = false }: {
+  viewId: string;
+  version: string;
+  slot: string;
+  active: boolean;
+  context: Record<string, unknown>;
+  adapter: ViewAdapter;
+  subscribeHidden(listener: () => void): () => void;
+  unavailable(): void;
+  focused?(): void;
+  focusOnReveal?: boolean;
+}) {
+  const mountRef = useRef<HTMLDivElement>(null);
+  const [loading, setLoading] = useState(true);
+  const adapterRef = useRef(adapter);
+  const unavailableRef = useRef(unavailable);
+  const focusedRef = useRef(focused);
+  const revealFocusRef = useRef(focusOnReveal);
+  const requestFocusRef = useRef<() => void>(() => {});
+  revealFocusRef.current = focusOnReveal;
+  focusedRef.current = focused;
+  adapterRef.current = adapter;
+  unavailableRef.current = unavailable;
+  useEffect(() => {
+    const mount = mountRef.current;
+    if (!active || !mount) return;
+    let cancelled = false;
+    const lifecycle = new PluginViewLifecycleController<HostedPluginViewState>();
+    const instanceId = crypto.randomUUID();
+    const scopeId = resolvePluginViewWindowScope({ pathname: window.location.pathname,
+      search: window.location.search, hash: `${window.location.hash}|plugin-slot:${slot}` });
+    const { openView, closeView, focusView, setViewBounds, setViewVisibility, onViewClosed, onViewFocused } = adapterRef.current;
+    const close = () => {
+      if (cancelled) return;
+      cancelled = true;
+      lifecycle.markViewClosed(viewId);
+      void closeView(instanceId).catch(() => {});
+    };
+    const failCurrent = () => {
+      if (cancelled) return;
+      close();
+      unavailableRef.current();
+    };
+    const unsubscribe = onViewClosed((event) => {
+      lifecycle.handleHostClose(event.instanceId);
+      if (event.instanceId === instanceId && !cancelled) {
+        close();
+        unavailableRef.current();
+      }
+    });
+    const stopOnHide = subscribeHidden(close);
+    const stopOnFocus = onViewFocused((event) => {
+      if (!cancelled && event.instanceId === instanceId) focusedRef.current?.();
+    });
+    const bounds = () => {
+      const rect = mount.getBoundingClientRect();
+      return { x: Math.round(rect.x), y: Math.round(rect.y), width: Math.max(1, Math.round(rect.width)), height: Math.max(1, Math.round(rect.height)) };
+    };
+    let opened = false;
+    let lastBounds = '';
+    let visible = false;
+    const focus = () => {
+      if (!cancelled && opened && visible && revealFocusRef.current && !isPluginViewOccluded(mount)) void focusView(instanceId).catch(() => {});
+    };
+    requestFocusRef.current = focus;
+    const updateVisibility = () => {
+      if (!opened || cancelled) return;
+      const rect = mount.getBoundingClientRect();
+      const next = rect.width > 0 && rect.height > 0 && !isPluginViewOccluded(mount);
+      if (visible === next) return;
+      visible = next;
+      void setViewVisibility(instanceId, next).then(() => { if (next) focus(); }).catch(failCurrent);
+    };
+    const resize = () => {
+      if (opened && !cancelled) {
+        const next = bounds();
+        const key = JSON.stringify(next);
+        if (key !== lastBounds) { lastBounds = key; void setViewBounds(instanceId, next).catch(failCurrent); }
+      }
+      updateVisibility();
+    };
+    const observer = typeof ResizeObserver === 'undefined' ? null : new ResizeObserver(resize);
+    observer?.observe(mount);
+    const mutations = new MutationObserver(resize);
+    mutations.observe(document.body, { childList: true, subtree: true, attributes: true,
+      attributeFilter: ['class', 'style', 'hidden', 'inert', 'role', 'aria-modal', 'aria-hidden', 'data-state', 'data-app-lock-overlay', 'data-radix-popper-content-wrapper', 'data-native-view-occluder'] });
+    window.addEventListener('resize', resize);
+    document.addEventListener('scroll', resize, true);
+    setLoading(true);
+    const opening = lifecycle.beginOpen({ viewKey: viewId });
+    void openView({ viewId, instanceId, scopeId, bounds: bounds(), context }).then(async (result) => {
+      if (cancelled || lifecycle.shouldCloseOpen(opening) || lifecycle.consumeHostClose(result.instanceId)) {
+        await closeView(result.instanceId);
+        return;
+      }
+      opened = true;
+      lifecycle.setCurrent({ id: result.instanceId, viewId, scopeId, retainContextWhenHidden: false });
+      resize();
+      setLoading(false);
+    }).catch(() => {
+      if (!cancelled) { close(); unavailableRef.current(); }
+    }).finally(() => lifecycle.finishOpen({ token: opening, viewKey: viewId }));
+    return () => {
+      close(); unsubscribe(); stopOnHide(); stopOnFocus(); observer?.disconnect(); mutations.disconnect();
+      window.removeEventListener('resize', resize); document.removeEventListener('scroll', resize, true);
+    };
+  }, [active, context, slot, subscribeHidden, version, viewId]);
+  useEffect(() => { if (focusOnReveal) requestFocusRef.current(); }, [focusOnReveal]);
+  return { mountRef, loading };
+}

application/state/usePluginContributions.ts

@@ -88,10 +88,12 @@ export interface UsePluginContributionsResult {
   selectSettingPath(kind: 'file' | 'directory', title: string, defaultPath?: string): Promise<string | null>;
   openView(payload: NetcattyPluginViewOpenRequest): Promise<{ instanceId: string }>;
   closeView(instanceId: string): Promise<void>;
+  focusView(instanceId: string): Promise<void>;
   setViewBounds(instanceId: string, bounds: { x: number; y: number; width: number; height: number }): Promise<void>;
   setViewVisibility(instanceId: string, visible: boolean): Promise<void>;
   setEnvironment(environment: NetcattyPluginEnvironment): Promise<void>;
   onViewClosed(callback: (event: NetcattyPluginViewClosedEvent) => void): () => void;
+  onViewFocused(callback: (event: import('@netcatty/plugin-contract').PluginViewFocusEvent) => void): () => void;
 }
 
 export function usePluginContributions(
@@ -196,6 +198,9 @@ export function usePluginContributions(
     if (!bridge?.closePluginView) return;
     await bridge.closePluginView(instanceId);
   }, [bridge]);
+  const focusView = useCallback(async (instanceId: string) => {
+    await bridge?.focusPluginView?.({ instanceId });
+  }, [bridge]);
 
   const setViewBounds = useCallback(async (
     instanceId: string,
@@ -218,6 +223,9 @@ export function usePluginContributions(
   const onViewClosed = useCallback((callback: (event: NetcattyPluginViewClosedEvent) => void) => (
     bridge?.onPluginViewClosed?.(callback) ?? (() => {})
   ), [bridge]);
+  const onViewFocused = useCallback((callback: (event: import('@netcatty/plugin-contract').PluginViewFocusEvent) => void) => (
+    bridge?.onPluginViewFocused?.(callback) ?? (() => {})
+  ), [bridge]);
 
   const currentLoadState = resolvePluginContributionLoadState({
     currentQueryKey: queryKey,
@@ -239,9 +247,11 @@ export function usePluginContributions(
     selectSettingPath,
     openView,
     closeView,
+    focusView,
     setViewBounds,
     setViewVisibility,
     setEnvironment,
     onViewClosed,
+    onViewFocused,
   };
 }

application/state/usePluginTerminalSidebar.ts

@@ -0,0 +1,79 @@
+import { useEffect, useMemo, useRef, useSyncExternalStore } from 'react';
+import { useI18n } from '../i18n/I18nProvider';
+import { toast } from '../../components/ui/toast';
+import { collectSidePanelPanes, isPluginSidePanelTool, type SidePanelLayout } from '../../domain/sidePanelLayout';
+import { activeTabStore, useActiveTabId } from './activeTabStore';
+import { getSidePanelLiveSnapshot, subscribeSidePanelLiveSnapshot } from './sidePanelLiveStore';
+import { usePluginContributions } from './usePluginContributions';
+import { OPEN_PLUGIN_VIEW_EVENT, type OpenPluginViewDetail } from './usePluginViewLifecycle';
+
+export const OPEN_PLUGIN_TERMINAL_SIDEBAR_EVENT = 'netcatty:open-plugin-terminal-sidebar';
+export const PLUGIN_TERMINAL_SIDEBAR_CONTEXT = Object.freeze({ 'netcatty.surface': 'terminal-sidebar' });
+/** Required production view-context projection, not a plugin-facing API. */
+export interface PluginSidebarHostActions {
+  getActiveTerminalSessionId(): string | null;
+  handleSwitchSidePanelTab(tool: import('../../domain/sidePanelLayout').SidePanelTool): void;
+  handleWithdrawPluginSidebarPane(tabId: string, paneId: string, expectedTool: import('../../domain/sidePanelLayout').SidePanelTool): void;
+}
+export interface PluginTerminalSidebarPage {
+  tool: `plugin-view:${string}`;
+  viewId: string;
+  pluginId: string;
+  pluginName: string;
+  version: string;
+  title: string;
+  icon?: NetcattyPluginIconReference;
+  order: number;
+}
+export function collectPluginTerminalSidebarPages(plugins: NetcattyPluginContributionSnapshot['plugins']): PluginTerminalSidebarPage[] {
+  return plugins.flatMap((plugin) => plugin.views.filter((view) => view.location === 'terminal-sidebar' && view.visible)
+    .map((view): PluginTerminalSidebarPage => ({ tool: `plugin-view:${view.id}`, viewId: view.id, pluginId: plugin.id,
+      pluginName: plugin.displayName, version: plugin.version, title: view.title, icon: view.icon, order: view.order ?? 0 })))
+    .sort((a, b) => a.order - b.order || a.viewId.localeCompare(b.viewId));
+}
+export function requestOpenPluginTerminalSidebar(viewId: string, sessionId: string) {
+  window.dispatchEvent(new CustomEvent(OPEN_PLUGIN_TERMINAL_SIDEBAR_EVENT, { detail: { viewId, sessionId } }));
+}
+export function usePluginTerminalSidebar(host: {
+  layouts: ReadonlyMap<string, SidePanelLayout>;
+  getSession(): string | null;
+  isTerminalTab(tabId: string): boolean;
+  select(tool: `plugin-view:${string}`): void;
+  withdraw(tabId: string, paneId: string, tool: `plugin-view:${string}`): void;
+}) {
+  const { locale, t } = useI18n();
+  const activeTabId = useActiveTabId();
+  // Follow workspace focus without subscribing the whole sidebar to cwd/title
+  // or forwarding the host's live session DTO to a plugin.
+  useSyncExternalStore((listener) => subscribeSidePanelLiveSnapshot(true, listener),
+    () => getSidePanelLiveSnapshot(true).focusedSessionId, () => null);
+  const hostRef = useRef(host); hostRef.current = host;
+  const contributions = usePluginContributions({ locale, context: PLUGIN_TERMINAL_SIDEBAR_CONTEXT });
+  const pages = useMemo(() => collectPluginTerminalSidebarPages(contributions.snapshot.plugins), [contributions.snapshot.plugins]);
+  const sessionId = activeTabId && host.isTerminalTab(activeTabId) ? host.getSession() : null;
+  useEffect(() => {
+    const open = (event: Event) => {
+      const detail = (event as CustomEvent<OpenPluginViewDetail & { sessionId?: string }>).detail;
+      const page = pages.find((item) => item.viewId === detail?.viewId);
+      if (!page) return;
+      const tabId = activeTabStore.getActiveTabId();
+      const current = hostRef.current.getSession();
+      if (!hostRef.current.isTerminalTab(tabId) || !current || (detail.sessionId && detail.sessionId !== current)) {
+        toast.info(t('plugins.sidebar.selectTerminal'));
+        return;
+      }
+      hostRef.current.select(page.tool);
+    };
+    window.addEventListener(OPEN_PLUGIN_TERMINAL_SIDEBAR_EVENT, open);
+    window.addEventListener(OPEN_PLUGIN_VIEW_EVENT, open);
+    return () => { window.removeEventListener(OPEN_PLUGIN_TERMINAL_SIDEBAR_EVENT, open); window.removeEventListener(OPEN_PLUGIN_VIEW_EVENT, open); };
+  }, [pages, t]);
+  useEffect(() => {
+    if (contributions.loading) return;
+    const allowed = new Set(pages.map((page) => page.tool));
+    for (const [tabId, layout] of host.layouts) for (const pane of collectSidePanelPanes(layout.root)) {
+      if (isPluginSidePanelTool(pane.tool) && !allowed.has(pane.tool)) host.withdraw(tabId, pane.id, pane.tool);
+    }
+  }, [contributions.loading, host, pages]);
+  return { pages, contributions, tabId: activeTabId, sessionId };
+}

application/state/usePluginThemeRuntime.ts

@@ -0,0 +1,77 @@
+import { useEffect, useSyncExternalStore } from "react";
+import { netcattyBridge } from "../../infrastructure/services/netcattyBridge";
+import { pluginThemeRegistry } from "../../infrastructure/config/pluginThemeRegistry";
+export function usePluginThemeRevision() {
+  return useSyncExternalStore(
+    pluginThemeRegistry.subscribe,
+    pluginThemeRegistry.getRevision,
+    pluginThemeRegistry.getRevision,
+  );
+}
+/** Host-owned selection; never stored in plugin KV or cloud sidecars. */
+let runtimeUsers = 0;
+let disconnectRuntime: (() => void) | undefined;
+function connectRuntime() {
+  const bridge = netcattyBridge.get();
+  let active = true,
+    request = 0;
+  const refresh = async () => {
+    const current = ++request;
+    try {
+      const catalog = await bridge?.getPluginThemes?.();
+      if (active && current === request && catalog)
+        pluginThemeRegistry.setCatalog(catalog);
+    } catch {
+      /* Keep the last host-validated selection; never apply unvalidated data. */
+    }
+  };
+  void refresh();
+  const dispose = bridge?.onPluginThemesChanged?.(() => {
+    pluginThemeRegistry.invalidate();
+    void refresh();
+  });
+  const forced = window.matchMedia?.("(forced-colors: active)"),
+    contrast = window.matchMedia?.("(prefers-contrast: more)");
+  const update = () =>
+    pluginThemeRegistry.setHighContrast(
+      Boolean(forced?.matches || contrast?.matches),
+    );
+  update();
+  forced?.addEventListener?.("change", update);
+  contrast?.addEventListener?.("change", update);
+  return () => {
+    active = false;
+    request++;
+    dispose?.();
+    forced?.removeEventListener?.("change", update);
+    contrast?.removeEventListener?.("change", update);
+  };
+}
+export function usePluginThemeRuntime() {
+  const revision = usePluginThemeRevision();
+  useEffect(() => {
+    if (runtimeUsers++ === 0) disconnectRuntime = connectRuntime();
+    return () => {
+      if (--runtimeUsers === 0) {
+        disconnectRuntime?.();
+        disconnectRuntime = undefined;
+      }
+    };
+  }, []);
+  return revision;
+}
+export async function applyPluginThemeSelection(
+  mode: "light" | "dark",
+  choice: import("@netcatty/plugin-contract").ThemePackChoice | null,
+) {
+  if (choice === null && !pluginThemeRegistry.isActive(mode))
+    return pluginThemeRegistry.getCatalog();
+  const bridge = netcattyBridge.require();
+  if (!bridge.applyPluginTheme) throw new Error("Plugin themes unavailable");
+  const next = await bridge.applyPluginTheme({
+    mode,
+    choice,
+    expectedRevision: pluginThemeRegistry.getCatalog().selection.revision,
+  });
+  return next; // The host change event refreshes every window; never publish a potentially stale apply response.
+}

application/state/usePluginVaultPages.ts

@@ -0,0 +1,47 @@
+import { useCallback, useEffect, useMemo, useRef } from 'react';
+import { activeTabStore, useActiveTabId } from './activeTabStore';
+import { collectPluginVaultPages, PLUGIN_VAULT_PAGE_PREFIX, resolvePluginVaultPage } from './pluginVaultPages';
+import { usePluginContributions } from './usePluginContributions';
+import { OPEN_PLUGIN_VIEW_EVENT, type OpenPluginViewDetail } from './usePluginViewLifecycle';
+
+const CONTEXT = Object.freeze({ 'netcatty.surface': 'vault-page' });
+
+export function usePluginVaultPages({ locale, section, select }: {
+  locale: string;
+  section: string;
+  select(section: 'hosts' | `plugin-vault:${string}`): void;
+}) {
+  const active = useActiveTabId() === 'vault';
+  const sectionRef = useRef(section);
+  const focusFrame = useRef<number | null>(null);
+  sectionRef.current = section;
+  useEffect(() => () => { if (focusFrame.current !== null) cancelAnimationFrame(focusFrame.current); }, []);
+  const contributions = usePluginContributions({ locale, context: CONTEXT });
+  const pages = useMemo(() => collectPluginVaultPages(contributions.snapshot.plugins), [contributions.snapshot.plugins]);
+  const selected = resolvePluginVaultPage(pages, section);
+  const fallback = useCallback(() => {
+    select('hosts');
+    if (focusFrame.current !== null) cancelAnimationFrame(focusFrame.current);
+    focusFrame.current = requestAnimationFrame(() => {
+      focusFrame.current = null;
+      if (sectionRef.current === 'hosts' && activeTabStore.getActiveTabId() === 'vault') {
+        document.querySelector<HTMLButtonElement>('[data-plugin-vault-fallback]')?.focus();
+      }
+    });
+  }, [select]);
+  useEffect(() => {
+    if (!contributions.loading && section.startsWith(PLUGIN_VAULT_PAGE_PREFIX) && !selected) fallback();
+  }, [contributions.loading, fallback, section, selected]);
+  useEffect(() => {
+    const open = (event: Event) => {
+      const detail = (event as CustomEvent<OpenPluginViewDetail>).detail;
+      const page = pages.find((item) => item.viewId === detail?.viewId);
+      if (!page) return;
+      activeTabStore.setActiveTabId('vault');
+      select(page.key);
+    };
+    window.addEventListener(OPEN_PLUGIN_VIEW_EVENT, open);
+    return () => window.removeEventListener(OPEN_PLUGIN_VIEW_EVENT, open);
+  }, [pages, select]);
+  return { pages, selected, active, select, fallback, contributions, context: CONTEXT };
+}

application/state/usePluginViewLifecycle.ts

@@ -82,7 +82,7 @@ export function usePluginViewLifecycle({
   const mountRef = useRef<HTMLDivElement>(null);
   const resolvedActiveView = useMemo(() => viewContributions.snapshot.plugins
     .flatMap((plugin) => plugin.views.map((view) => ({ plugin, view })))
-    .find(({ view }) => view.id === effectiveRequested?.viewId && view.visible) ?? null,
+    .find(({ view }) => view.id === effectiveRequested?.viewId && view.visible && !['vault-page', 'terminal-sidebar'].includes(view.location)) ?? null,
   [effectiveRequested?.viewId, viewContributions.snapshot.plugins]);
   const stableActiveViewRef = useRef<PluginViewSnapshotSelection<ResolvedPluginView> | null>(null);
   const activeView = resolvePluginViewSnapshotSelection({

application/state/useSettingsState.ts

@@ -1,3 +1,4 @@
+import { usePluginThemeRuntime } from './usePluginThemeRuntime';
 import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState, type SetStateAction } from 'react';
 
 import { runThemeTransition, type ThemeTransitionMode } from './themeTransition';
@@ -217,6 +218,7 @@ import {
 } from './appearanceSync';
 
 export const useSettingsState = (options: { enableSettingsSync?: boolean; enableSystemEffects?: boolean } = {}) => {
+  const pluginThemeRevision = usePluginThemeRuntime();
   const enableSettingsSync = options.enableSettingsSync !== false;
   const enableSystemEffects = options.enableSystemEffects !== false;
   const initialCustomKeyBindingsRecord =
@@ -1212,7 +1214,7 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
         notifySettingsChanged(STORAGE_KEY_COLOR, customAccentRecord);
       }
     }
-  }, [theme, resolvedTheme, lightUiThemeId, darkUiThemeId, accentMode, customAccent, customAccentRecord, notifySettingsChanged]);
+  }, [theme, resolvedTheme, lightUiThemeId, darkUiThemeId, accentMode, customAccent, customAccentRecord, notifySettingsChanged, pluginThemeRevision]);
 
   // Listen for OS color scheme changes to keep systemPreference in sync
   useEffect(() => {
@@ -1979,9 +1981,10 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
   }, [setTerminalSettings]);
 
   const applyAppTheme = useCallback(() => {
+    void pluginThemeRevision; // Invalidate the closure when host theme data changes.
     const tokens = getUiThemeById(resolvedTheme, resolvedTheme === 'dark' ? darkUiThemeId : lightUiThemeId).tokens;
     applyThemeTokens(theme, resolvedTheme, tokens, accentMode, customAccent);
-  }, [theme, resolvedTheme, lightUiThemeId, darkUiThemeId, accentMode, customAccent]);
+  }, [theme, resolvedTheme, lightUiThemeId, darkUiThemeId, accentMode, customAccent, pluginThemeRevision]);
 
   const setEditorWordWrap = useCallback((enabled: boolean) => {
     setEditorWordWrapState(enabled);

components/KeychainManager.tsx

@@ -882,6 +882,7 @@ echo $3 >> "$FILE"`);
       {/* Slide-out Panel */}
       {panel.type !== "closed" && (
         <AsidePanel
+          dataSection="keychain-security-panel"
           open={true}
           onClose={closePanel}
           title={panelTitle}

components/PluginTerminalSidebar.test.tsx

@@ -0,0 +1,128 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { JSDOM } from 'jsdom';
+
+test('terminal extension pages use actual split panes, focus and session ownership without sharing session data', async () => {
+  const dom = new JSDOM('<!doctype html><html><body><div id="root"></div></body></html>', { pretendToBeVisual: true, url: 'http://localhost' });
+  const previous = new Map<string, PropertyDescriptor | undefined>();
+  const install = (key: string, value: unknown) => {
+    previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key)); Object.defineProperty(globalThis, key, { configurable: true, writable: true, value });
+  };
+  for (const key of ['window', 'document', 'navigator', 'HTMLElement', 'HTMLInputElement', 'Element', 'SVGElement', 'Node', 'NodeFilter', 'MutationObserver', 'CustomEvent', 'Event', 'KeyboardEvent', 'MouseEvent']) {
+    install(key, key === 'window' ? dom.window : dom.window[key as keyof typeof dom.window]);
+  }
+  install('PointerEvent', dom.window.MouseEvent);
+  install('getComputedStyle', dom.window.getComputedStyle.bind(dom.window));
+  install('requestAnimationFrame', dom.window.requestAnimationFrame.bind(dom.window)); install('cancelAnimationFrame', dom.window.cancelAnimationFrame.bind(dom.window)); install('IS_REACT_ACT_ENVIRONMENT', true);
+  let rectX = 200;
+  dom.window.HTMLElement.prototype.getBoundingClientRect = () => new dom.window.DOMRect(rectX, 100, 400, 300);
+  const { default: React, act, useCallback, useRef, useState } = await import('react');
+  const { createRoot } = await import('react-dom/client');
+  const { I18nProvider } = await import('../application/i18n/I18nProvider');
+  const { activeTabStore } = await import('../application/state/activeTabStore');
+  const { sidePanelLiveStore, SIDE_PANEL_INACTIVE_LIVE_SNAPSHOT } = await import('../application/state/sidePanelLiveStore');
+  const { useTerminalSidePanelLayoutState } = await import('../application/state/useTerminalSidePanelLayoutState');
+  const { usePluginTerminalSidebar } = await import('../application/state/usePluginTerminalSidebar');
+  const { PluginTerminalSidebarLauncher, PluginTerminalSidebarPageHost } = await import('./plugins/PluginTerminalSidebar');
+  const { SidePanelLayoutTree } = await import('./terminalLayer/TerminalLayerSidePanelSection');
+  const { PersistentSidePanelPortal } = await import('./terminalLayer/terminalLayerSidePanelSlots');
+  const { collectSidePanelPanes } = await import('../domain/sidePanelLayout');
+  type Tool = import('../domain/sidePanelLayout').SidePanelTool;
+  let selectedSession = 'synthetic-session-a';
+  const getSession = () => selectedSession;
+  const a = { id: 'com.example.sidebar.first', title: 'First page', location: 'terminal-sidebar', entry: 'page.html', visible: true };
+  const b = { ...a, id: 'com.example.sidebar.second', title: 'Second page' };
+  let snapshot = { locale: 'en', plugins: [{ id: 'com.example.sidebar', displayName: 'Synthetic plugin', version: '1.0.0', commands: [], keybindings: [], menus: [], settings: [], views: [a, b] }] };
+  const changed = new Set<() => void>(), focusListeners = new Set<(event: { instanceId: string }) => void>();
+  const opens: NetcattyPluginViewOpenRequest[] = [], closes: string[] = [], focus: string[] = [], bounds: Array<{ instanceId: string; x: number }> = [];
+  const visible = new Map<string, boolean>();
+  Object.assign(dom.window, { netcatty: {
+    async getPluginRuntimeStatus() { return { available: true }; }, async getPluginContributions() { return snapshot; },
+    onPluginContributionsChanged(fn: () => void) { changed.add(fn); return () => { changed.delete(fn); }; },
+    onPluginViewClosed() { return () => {}; },
+    onPluginViewFocused(fn: (event: { instanceId: string }) => void) { focusListeners.add(fn); return () => { focusListeners.delete(fn); }; },
+    async openPluginView(payload: NetcattyPluginViewOpenRequest) { opens.push(payload); return { instanceId: payload.instanceId! }; },
+    async closePluginView(id: string) { closes.push(id); },
+    async setPluginViewBounds(id: string, rect: { x: number }) { bounds.push({ instanceId: id, x: rect.x }); },
+    async setPluginViewVisibility(id: string, value: boolean) { visible.set(id, value); },
+    async focusPluginView(event: { instanceId: string }) { focus.push(event.instanceId); for (const fn of focusListeners) fn(event); },
+  } });
+  let split!: () => void;
+  function Fixture() {
+    const state = useTerminalSidePanelLayoutState(); const latest = useRef(state); latest.current = state;
+    const model = usePluginTerminalSidebar({ layouts: state.sidePanelLayouts, getSession, isTerminalTab: (id) => id === 'workspace-synthetic' || id === 'synthetic-local-terminal',
+      select: (tool) => state.selectSidePanelToolForTab(activeTabStore.getActiveTabId(), tool),
+      withdraw: (tabId, paneId, tool) => {
+        const layout = state.sidePanelLayoutsRef.current.get(tabId);
+        if (layout && collectSidePanelPanes(layout.root).some((pane) => pane.id === paneId && pane.tool === tool)) state.closePane(tabId, paneId);
+      } });
+    const [hosts, setHosts] = useState(new Map<Tool, HTMLElement>()); const parking = useRef<HTMLDivElement>(null);
+    const register = useCallback((tool: Tool, host: HTMLElement | null) => setHosts((prior) => {
+      if ((prior.get(tool) ?? null) === host) return prior;
+      const next = new Map(prior); if (host) next.set(tool, host); else next.delete(tool); return next;
+    }), []);
+    const focusPane = useCallback((id: string) => latest.current.focusPane(activeTabStore.getActiveTabId(), id), []);
+    const closePane = useCallback((id: string) => { latest.current.closePane(activeTabStore.getActiveTabId(), id); }, []);
+    const resize = useCallback(() => {}, []);
+    const layout = model.tabId ? state.sidePanelLayouts.get(model.tabId) : null;
+    const panes = layout ? collectSidePanelPanes(layout.root) : [];
+    split = () => state.splitPane('workspace-synthetic', `plugin-view:${b.id}`, 'vertical', { paneId: 'second-pane', splitId: 'plugin-split' }, 600);
+    return <><PluginTerminalSidebarLauncher sessionId={selectedSession} />
+      {layout && <SidePanelLayoutTree node={layout.root} layout={layout} paneCount={panes.length} labels={new Map(model.pages.map((page) => [page.tool, page.title]))}
+        onClose={closePane} onFocus={focusPane} onHostChange={register} onResize={resize} separator="#777" accent="#4488cc" closePaneLabel="Close pane" resizeLabel="Resize" />}
+      <div ref={parking} hidden aria-hidden="true" />
+      {model.sessionId && panes.map((pane) => {
+        const page = model.pages.find((item) => item.tool === pane.tool); const target = hosts.get(pane.tool) ?? parking.current;
+        if (!page || !target) return null;
+        return <PersistentSidePanelPortal key={`${pane.id}:${model.sessionId}`} portalKey={`plugin-${pane.id}`} target={target}>
+          <PluginTerminalSidebarPageHost page={page} tabId={model.tabId!} sessionId={model.sessionId} getSession={getSession} adapter={model.contributions}
+            focusOnReveal={layout?.focusedPaneId === pane.id} focused={() => focusPane(pane.id)} unavailable={() => closePane(pane.id)} />
+        </PersistentSidePanelPortal>;
+      })}</>;
+  }
+  const root = createRoot(document.getElementById('root')!); const settle = () => new Promise((resolve) => setTimeout(resolve, 40));
+  try {
+    activeTabStore.setActiveTabId('workspace-synthetic'); sidePanelLiveStore.update({ ...SIDE_PANEL_INACTIVE_LIVE_SNAPSHOT, focusedSessionId: selectedSession });
+    await act(async () => { root.render(<I18nProvider locale="en"><Fixture /></I18nProvider>); await settle(); });
+    await act(async () => { document.querySelector<HTMLButtonElement>('button[aria-label="Extension pages"]')!.click(); await settle(); });
+    const firstButton = [...document.querySelectorAll('button')].find((button) => button.textContent?.includes('First page'))!;
+    await act(async () => { firstButton.click(); await settle(); });
+    assert.equal(document.querySelectorAll('[data-section="terminal-side-panel-pane"]').length, 1);
+    assert.ok(document.querySelector('[data-pane-tool] [data-plugin-view-slot="terminal-sidebar"]'));
+    assert.equal(opens.length, 1); assert.deepEqual(opens[0].context, { 'netcatty.surface': 'terminal-sidebar' });
+    await act(async () => { split(); await settle(); });
+    assert.equal(document.querySelectorAll('[data-section="terminal-side-panel-pane"]').length, 2);
+    assert.equal(opens.length, 2);
+    const firstId = opens.find((item) => item.viewId === a.id)!.instanceId!;
+    await act(async () => { for (const fn of focusListeners) fn({ instanceId: firstId }); await settle(); });
+    assert.equal(document.querySelector(`[data-pane-tool="plugin-view:${a.id}"]`)?.getAttribute('data-focused'), 'true');
+    const dialog = document.createElement('div'); dialog.setAttribute('role', 'dialog'); dialog.setAttribute('aria-modal', 'true');
+    await act(async () => { document.body.append(dialog); await settle(); });
+    assert.ok(opens.every((item) => visible.get(item.instanceId!) === false));
+    focus.length = 0;
+    await act(async () => { dialog.remove(); await settle(); });
+    assert.ok(focus.length > 0); assert.ok(focus.every((id) => id === firstId), 'restoring panes focuses only the host-selected pane');
+    const old = opens.map((item) => item.instanceId!);
+    await act(async () => { selectedSession = 'synthetic-session-b'; sidePanelLiveStore.update({ ...SIDE_PANEL_INACTIVE_LIVE_SNAPSHOT, focusedSessionId: selectedSession });
+      assert.ok(old.every((id) => closes.includes(id)), 'workspace focus cancels old native owners synchronously'); await settle(); });
+    assert.equal(opens.length, 4);
+    assert.notEqual(opens[0].scopeId, opens[2].scopeId);
+    assert.ok(opens.every((item) => JSON.stringify(item.context) === JSON.stringify({ 'netcatty.surface': 'terminal-sidebar' })));
+    await act(async () => { rectX = 260; snapshot = { ...snapshot, plugins: [{ ...snapshot.plugins[0], views: [{ ...a, visible: false }, b] }] }; for (const fn of changed) fn(); await settle(); });
+    assert.equal(document.querySelectorAll('[data-section="terminal-side-panel-pane"]').length, 1);
+    assert.equal(document.querySelector('[data-pane-tool]')?.getAttribute('data-pane-tool'), `plugin-view:${b.id}`);
+    assert.ok(bounds.some((item) => item.x === 260), 'portal relocation updates native geometry');
+    const last = opens.at(-1)!.instanceId!;
+    await act(async () => { activeTabStore.setActiveTabId('vault'); assert.ok(closes.includes(last)); await settle(); });
+    assert.equal(document.querySelector('[data-plugin-terminal-sidebar]'), null);
+    await act(async () => { selectedSession = 'synthetic-local-terminal'; activeTabStore.setActiveTabId(selectedSession); await settle(); });
+    await act(async () => { document.querySelector<HTMLButtonElement>('button[aria-label="Extension pages"]')!.click(); await settle(); });
+    const localPage = [...document.querySelectorAll('button')].find((button) => button.textContent?.includes('Second page'))!;
+    await act(async () => { localPage.click(); await settle(); });
+    assert.ok(document.querySelector('[data-plugin-view-slot="terminal-sidebar"]'), 'standalone Local Terminal is a valid navigation owner');
+    assert.deepEqual(opens.at(-1)!.context, { 'netcatty.surface': 'terminal-sidebar' });
+  } finally {
+    await act(async () => { root.unmount(); await settle(); }); dom.window.close();
+    for (const [key, descriptor] of previous) { if (descriptor) Object.defineProperty(globalThis, key, descriptor); else Reflect.deleteProperty(globalThis, key); }
+  }
+});

components/PluginVaultPages.test.tsx

@@ -0,0 +1,101 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { JSDOM } from 'jsdom';
+
+test('Vault navigation mounts a real content slot, yields to host dialogs, and withdraws stale pages', async () => {
+  const dom = new JSDOM('<!doctype html><html><body><div id="root"></div></body></html>', { pretendToBeVisual: true, url: 'http://localhost' });
+  const previous = new Map<string, PropertyDescriptor | undefined>();
+  for (const key of ['window', 'document', 'navigator', 'HTMLElement', 'Element', 'Node', 'MutationObserver', 'CustomEvent', 'Event']) {
+    previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key));
+    Object.defineProperty(globalThis, key, { configurable: true, writable: true, value: key === 'window' ? dom.window : dom.window[key as keyof Window] });
+  }
+  for (const [key, value] of Object.entries({ getComputedStyle: dom.window.getComputedStyle.bind(dom.window),
+    requestAnimationFrame: dom.window.requestAnimationFrame.bind(dom.window), cancelAnimationFrame: dom.window.cancelAnimationFrame.bind(dom.window), IS_REACT_ACT_ENVIRONMENT: true })) {
+    previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key)); Object.defineProperty(globalThis, key, { configurable: true, writable: true, value });
+  }
+  dom.window.HTMLElement.prototype.getBoundingClientRect = () => ({ x: 200, y: 100, width: 640, height: 480, top: 100, left: 200, right: 840, bottom: 580, toJSON() {} });
+  const { default: React, act, useState } = await import('react');
+  const { createRoot } = await import('react-dom/client');
+  const { usePluginVaultPages } = await import('../application/state/usePluginVaultPages');
+  const { PluginVaultNavigation, PluginVaultPage } = await import('./plugins/PluginVaultPages');
+  const { activeTabStore } = await import('../application/state/activeTabStore');
+  const { requestOpenPluginView } = await import('../application/state/usePluginViewLifecycle');
+  const { I18nProvider } = await import('../application/i18n/I18nProvider');
+  const page = { id: 'com.example.page.main', title: 'Synthetic page', location: 'vault-page', entry: 'page.html', visible: true };
+  let snapshot = { locale: 'en', plugins: [{ id: 'com.example.page', version: '1.0.0', displayName: 'Synthetic plugin', commands: [], keybindings: [], menus: [], settings: [], views: [page] }] };
+  let changed: (() => void) | undefined;
+  const listeners = new Set<(event: NetcattyPluginViewClosedEvent) => void>();
+  const opens: NetcattyPluginViewOpenRequest[] = [], closes: string[] = [], visibility: boolean[] = [];
+  let defer: ((value: { instanceId: string }) => void) | undefined;
+  let deferOpen = false;
+  let delayLayout = false;
+  const rejectOldLayout: Array<(error: Error) => void> = [];
+  const layoutResult = () => delayLayout ? new Promise<void>((_resolve, reject) => { rejectOldLayout.push(reject); }) : Promise.resolve();
+  Object.assign(dom.window, { netcatty: {
+    async getPluginRuntimeStatus() { return { available: true }; },
+    async getPluginContributions() { return snapshot; },
+    onPluginContributionsChanged(fn: () => void) { changed = fn; return () => { changed = undefined; }; },
+    onPluginViewClosed(fn: (event: NetcattyPluginViewClosedEvent) => void) { listeners.add(fn); return () => { listeners.delete(fn); }; },
+    async openPluginView(payload: NetcattyPluginViewOpenRequest) { opens.push(payload); return deferOpen ? new Promise<{ instanceId: string }>((resolve) => { defer = resolve; }) : { instanceId: payload.instanceId! }; },
+    async closePluginView(id: string) { closes.push(id); }, async setPluginViewBounds() { await layoutResult(); },
+    async setPluginViewVisibility(_id: string, visible: boolean) { visibility.push(visible); await layoutResult(); },
+  } });
+  let selectSection!: (section: 'hosts' | `plugin-vault:${string}`) => void;
+  function Fixture() {
+    const [section, select] = useState<'hosts' | `plugin-vault:${string}`>('hosts'); selectSection = select;
+    const model = usePluginVaultPages({ locale: 'en', section, select });
+    return <><aside><button data-plugin-vault-fallback onClick={() => select('hosts')}>Hosts</button><PluginVaultNavigation model={model} collapsed={false} /></aside>
+      <main data-section="vault-main">{model.selected ? <PluginVaultPage key={model.selected.key} model={model} /> : <p>Built-in hosts</p>}</main></>;
+  }
+  const root = createRoot(document.getElementById('root')!);
+  const settle = () => new Promise((resolve) => setTimeout(resolve, 35));
+  const clickPage = async () => { await act(async () => { document.querySelector<HTMLButtonElement>('button[aria-label="Synthetic page — Synthetic plugin"]')!.click(); await settle(); }); };
+  try {
+    activeTabStore.setActiveTabId('vault');
+    await act(async () => { root.render(<I18nProvider locale="en"><Fixture /></I18nProvider>); await settle(); });
+    assert.equal(opens.length, 0, 'catalog enumeration does not activate the plugin');
+    await clickPage();
+    assert.ok(document.querySelector('[data-section="vault-main"] [data-plugin-view-slot="vault-page"]'));
+    assert.equal(opens.length, 1);
+    assert.deepEqual(opens[0].context, { 'netcatty.surface': 'vault-page' }, 'no Vault/session data accompanies navigation');
+    assert.equal(visibility.at(-1), true);
+    const dialog = document.createElement('div'); dialog.setAttribute('role', 'dialog'); dialog.setAttribute('aria-modal', 'true');
+    await act(async () => { document.body.append(dialog); await settle(); });
+    assert.equal(visibility.at(-1), false, 'native content yields to host security/settings dialogs');
+    await act(async () => { dialog.remove(); await settle(); });
+    assert.equal(visibility.at(-1), true);
+    await act(async () => { activeTabStore.setActiveTabId('terminal:synthetic'); assert.ok(closes.includes(opens[0].instanceId!)); await settle(); });
+    await act(async () => { activeTabStore.setActiveTabId('vault'); await settle(); });
+    assert.equal(opens.length, 2);
+    await act(async () => { snapshot = { ...snapshot, plugins: [] }; changed?.(); await settle(); });
+    await act(async () => { await settle(); });
+    assert.ok(closes.includes(opens[1].instanceId!));
+    assert.equal(document.querySelector('[data-plugin-vault-page]'), null);
+    assert.equal(document.activeElement?.textContent, 'Hosts');
+    await act(async () => { selectSection('plugin-vault:missing'); await settle(); });
+    assert.match(document.querySelector('main')!.textContent!, /Built-in hosts/);
+    await act(async () => { snapshot = { ...snapshot, plugins: [{ id: 'com.example.page', version: '1.0.0', displayName: 'Synthetic plugin', commands: [], keybindings: [], menus: [], settings: [], views: [page] }] }; changed?.(); await settle(); });
+    deferOpen = true;
+    await act(async () => { requestOpenPluginView({ viewId: page.id }); await settle(); });
+    assert.equal(opens.length, 3);
+    await act(async () => { selectSection('hosts'); await settle(); });
+    assert.ok(closes.includes(opens[2].instanceId!), 'cancel reserved instance before its open response');
+    await act(async () => { defer!({ instanceId: opens[2].instanceId! }); await settle(); });
+    assert.equal(document.querySelector('[data-plugin-vault-page]'), null, 'late open cannot restore withdrawn page');
+    assert.ok(closes.filter((id) => id === opens[2].instanceId).length >= 2, 'late native response is also closed');
+    deferOpen = false;
+    const second = { ...page, id: 'com.example.page.second', title: 'Second page' };
+    await act(async () => { snapshot = { ...snapshot, plugins: [{ ...snapshot.plugins[0], views: [page, second] }] }; changed?.(); await settle(); });
+    delayLayout = true;
+    await clickPage();
+    assert.ok(rejectOldLayout.length >= 2, 'old page has both bounds and visibility IPC in flight');
+    await act(async () => { selectSection('hosts'); await settle(); });
+    delayLayout = false;
+    await act(async () => { document.querySelector<HTMLButtonElement>('button[aria-label="Second page — Synthetic plugin"]')!.click(); await settle(); });
+    await act(async () => { for (const reject of rejectOldLayout) reject(new Error('old page layout failed')); await settle(); });
+    assert.equal(document.querySelector('[data-plugin-vault-page]')?.getAttribute('aria-label'), 'Second page', 'old bounds/visibility failures cannot withdraw the newly selected page');
+  } finally {
+    await act(async () => { root.unmount(); await settle(); }); dom.window.close();
+    for (const [key, descriptor] of previous) { if (descriptor) Object.defineProperty(globalThis, key, descriptor); else Reflect.deleteProperty(globalThis, key); }
+  }
+});

components/SettingsPage.tsx

@@ -1,3 +1,5 @@
+import { useAppThemeStyle } from "../application/app/useAppThemeStyle";
+import { selectPluginThemeTokens } from "../application/state/pluginContributionEnvironment";
 /**
  * Settings Page - Standalone settings window content
  * This component is rendered in a separate Electron window
@@ -322,6 +324,9 @@ const SettingsSyncTabWithVault: React.FC<{ onSettingsApplied?: () => void }> = (
 };
 
 const SettingsPageContent: React.FC<{ settings: SettingsState; appLock?: AppLockState }> = ({ settings, appLock }) => {
+    // This publisher also runs in detached Settings: never broadcast a local preview.
+    const committedAppThemeStyle = useAppThemeStyle(false);
+    const pluginThemeTokens = useMemo(() => selectPluginThemeTokens(committedAppThemeStyle as Record<string, unknown>), [committedAppThemeStyle]);
     const { t } = useI18n();
     const { request, clearFocus, openSearch } = useSettingsFocus();
     const { notifyRendererReady, closeSettingsWindow, onWindowCommandCloseRequested } = useWindowControls();
@@ -715,7 +720,7 @@ const SettingsPageContent: React.FC<{ settings: SettingsState; appLock?: AppLock
             </Tabs>
         </div>
         <ExternalMcpApprovalsHost />
-        <PluginContributionHost locale={settings.uiLanguage} theme={settings.resolvedTheme} />
+        <PluginContributionHost locale={settings.uiLanguage} theme={settings.resolvedTheme} themeTokens={pluginThemeTokens} />
         </>
     );
 };

components/TerminalLayer.tsx

@@ -123,6 +123,7 @@ import {
 import { classifyDistroId, hostRestrictsExtraSshChannels, shouldProbeSessionCwd } from '../domain/host';
 import {
   collectSidePanelPanes,
+  isPluginSidePanelTool,
   sidePanelLayoutHasTool,
   type SidePanelLayout,
   type SidePanelSplitDirection,
@@ -1933,6 +1934,16 @@ const TerminalLayerInner: React.FC<TerminalLayerProps> = ({
     resizeSidePanelSplitForTab(tabId, splitId, sizes);
   }, [resizeSidePanelSplitForTab]);
 
+  const handleWithdrawPluginSidebarPane = useCallback((tabId: string, paneId: string, expectedTool: SidePanelTab) => {
+    if (!isPluginSidePanelTool(expectedTool)) return;
+    const layout = sidePanelLayoutsRef.current.get(tabId);
+    const pane = layout && collectSidePanelPanes(layout.root).find((item) => item.id === paneId);
+    if (pane?.tool !== expectedTool) return;
+    setMagnifiedPane((current) => current?.tabId === tabId && current.target.kind === 'side-panel'
+      && current.target.paneId === paneId ? null : current);
+    closeSidePanelPaneForTab(tabId, paneId);
+  }, [closeSidePanelPaneForTab, sidePanelLayoutsRef]);
+
   // Toggle SFTP from activity bar header
   const handleToggleSftpFromBar = useCallback(() => {
     handleSwitchSidePanelTab('sftp');
@@ -2617,6 +2628,9 @@ const TerminalLayerInner: React.FC<TerminalLayerProps> = ({
     handleOpenAI,
     handleOpenSystem,
     handleOpenNotes,
+    getActiveTerminalSessionId,
+    handleSwitchSidePanelTab,
+    handleWithdrawPluginSidebarPane,
     handleOpenBrowser,
     handleFocusSidePanelPane,
     handleMagnifySidePanelPane,

components/VaultView.tsx

@@ -161,6 +161,7 @@ import { VaultViewLayout } from "./vault/VaultViewLayout";
 import { useVaultHostCollections } from "./vault/useVaultHostCollections";
 import { useVaultImportHandlers } from "../application/state/useVaultImportHandlers";
 import { useVaultGroupDragHandlers } from "./vault/useVaultGroupDragHandlers";
+import { usePluginVaultPages } from "../application/state/usePluginVaultPages";
 
 const LazyProtocolSelectDialog = lazy(() => import("./ProtocolSelectDialog"));
 const LazyConnectionLogsManager = lazy(() => import("./ConnectionLogsManager"));
@@ -178,7 +179,8 @@ export type VaultSection =
   | "notes"
   | "port"
   | "knownhosts"
-  | "logs";
+  | "logs"
+  | `plugin-vault:${string}`;
 
 const haveSameHostOrderResult = (previous: Host[], next: Host[]) => {
   if (previous.length !== next.length) return false;
@@ -365,11 +367,12 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
   onVaultFocusRequestHandled,
   terminalSettings,
 }) => {
-  const { t } = useI18n();
+  const { t, locale } = useI18n();
   const rootRef = useRef<HTMLDivElement>(null);
   const hostsRef = useRef(hosts);
   hostsRef.current = hosts;
   const [currentSection, setCurrentSection] = useState<VaultSection>("hosts");
+  const pluginVault = usePluginVaultPages({ locale, section: currentSection, select: setCurrentSection });
   const [search, setSearch] = useState("");
   const [selectedGroupPath, setSelectedGroupPath] = useState<string | null>(
     null,
@@ -1522,6 +1525,7 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
           ContextMenuTrigger,
           Copy,
           currentSection,
+          pluginVault,
           customGroups,
           deleteGroupPath,
           deleteGroupPaths,

components/plugins/PluginTerminalSidebar.tsx

@@ -0,0 +1,56 @@
+import { useMemo } from 'react';
+import { Blocks } from 'lucide-react';
+import { useI18n } from '../../application/i18n/I18nProvider';
+import { activeTabStore } from '../../application/state/activeTabStore';
+import { subscribeSidePanelLiveSnapshot } from '../../application/state/sidePanelLiveStore';
+import { useEmbeddedPluginView } from '../../application/state/useEmbeddedPluginView';
+import { usePluginContributions } from '../../application/state/usePluginContributions';
+import { collectPluginTerminalSidebarPages, PLUGIN_TERMINAL_SIDEBAR_CONTEXT, requestOpenPluginTerminalSidebar,
+  type PluginTerminalSidebarPage } from '../../application/state/usePluginTerminalSidebar';
+import { PluginContributionIcon } from './PluginContributionIcon';
+import { Button } from '../ui/button';
+import { Popover, PopoverClose, PopoverContent, PopoverTrigger } from '../ui/popover';
+
+export function PluginTerminalSidebarLauncher({ sessionId }: { sessionId: string }) {
+  const { locale, t } = useI18n();
+  const contributions = usePluginContributions({ locale, context: PLUGIN_TERMINAL_SIDEBAR_CONTEXT });
+  const pages = collectPluginTerminalSidebarPages(contributions.snapshot.plugins);
+  if (!pages.length) return null;
+  return <Popover><PopoverTrigger asChild><Button variant="ghost" size="icon" className="h-6 w-6" aria-label={t('plugins.sidebar.extensions')}><Blocks size={14} /></Button></PopoverTrigger>
+    <PopoverContent align="end" className="max-h-80 w-64 overflow-y-auto p-1">
+      <p className="px-2 py-1 text-xs text-muted-foreground">{t('plugins.sidebar.extensions')}</p>
+      {pages.map((page) => <PopoverClose asChild key={page.tool}><button type="button" className="flex w-full items-center gap-2 rounded px-2 py-2 text-left text-sm hover:bg-accent"
+        onClick={() => requestOpenPluginTerminalSidebar(page.viewId, sessionId)}>
+        <PluginContributionIcon pluginId={page.pluginId} icon={page.icon} /><span className="min-w-0"><span className="block truncate">{page.title}</span><span className="block truncate text-xs text-muted-foreground">{page.pluginName}</span></span>
+      </button></PopoverClose>)}
+    </PopoverContent></Popover>;
+}
+
+export function PluginTerminalSidebarPageHost({ page, tabId, sessionId, adapter, getSession, unavailable, focused, focusOnReveal }: {
+  page: PluginTerminalSidebarPage;
+  tabId: string;
+  sessionId: string;
+  adapter: ReturnType<typeof usePluginContributions>;
+  getSession(): string | null;
+  unavailable(): void;
+  focused(): void;
+  focusOnReveal: boolean;
+}) {
+  const { t } = useI18n();
+  const subscribeHidden = useMemo(() => (hide: () => void) => {
+    const stopTab = activeTabStore.subscribeSync((id) => { if (id !== tabId) hide(); });
+    const stopSession = subscribeSidePanelLiveSnapshot(true, () => { if (getSession() !== sessionId) hide(); });
+    return () => { stopTab(); stopSession(); };
+  }, [getSession, sessionId, tabId]);
+  const { mountRef, loading } = useEmbeddedPluginView({ viewId: page.viewId, version: page.version,
+    slot: `terminal-sidebar:${tabId}:${sessionId}`, active: true, context: PLUGIN_TERMINAL_SIDEBAR_CONTEXT,
+    adapter, subscribeHidden, unavailable, focused, focusOnReveal });
+  // The native page never receives these internal ownership IDs. Its state is
+  // scoped by the host; this does not authorize reading the terminal session.
+  return <section className="flex h-full min-h-0 flex-col overflow-hidden" aria-label={`${page.title} — ${page.pluginName}`} data-plugin-terminal-sidebar>
+    <header className="flex h-7 shrink-0 items-center gap-2 border-b border-border px-2 text-xs"><PluginContributionIcon pluginId={page.pluginId} icon={page.icon} size={12} /><span className="truncate">{page.title} · {page.pluginName}</span></header>
+    <div ref={mountRef} className="relative min-h-0 flex-1 overflow-hidden" data-plugin-view-slot="terminal-sidebar">
+      {loading && <p role="status" className="p-3 text-xs text-muted-foreground">{t('plugins.sidebar.loading')}</p>}
+    </div>
+  </section>;
+}

components/plugins/PluginVaultPages.tsx

@@ -0,0 +1,44 @@
+import { activeTabStore } from '../../application/state/activeTabStore';
+import { useI18n } from '../../application/i18n/I18nProvider';
+import { useEmbeddedPluginView } from '../../application/state/useEmbeddedPluginView';
+import type { usePluginVaultPages } from '../../application/state/usePluginVaultPages';
+import { PluginContributionIcon } from './PluginContributionIcon';
+import { Button } from '../ui/button';
+
+type VaultPages = ReturnType<typeof usePluginVaultPages>;
+const subscribeHidden = (hide: () => void) => activeTabStore.subscribeSync((id) => { if (id !== 'vault') hide(); });
+
+export function PluginVaultNavigation({ model, collapsed }: { model: VaultPages; collapsed: boolean }) {
+  const { t } = useI18n();
+  if (!model.pages.length) return null;
+  return <div role="group" aria-label={t('plugins.vault.extensions')} className="mt-3 space-y-1 border-t border-border/50 pt-3">
+    {!collapsed && <p className="px-2 text-xs text-muted-foreground">{t('plugins.vault.extensions')}</p>}
+    {model.pages.map((page) => <Button key={page.key} type="button"
+      variant={model.selected?.key === page.key ? 'secondary' : 'ghost'}
+      className={`w-full ${collapsed ? 'justify-center px-0' : 'justify-start gap-3'}`}
+      title={`${page.title} — ${page.pluginName}`}
+      aria-label={`${page.title} — ${page.pluginName}`}
+      aria-current={model.selected?.key === page.key ? 'page' : undefined}
+      onClick={() => model.select(page.key)}>
+      <PluginContributionIcon pluginId={page.pluginId} icon={page.icon} className="shrink-0" />
+      {!collapsed && <span className="truncate">{page.title}</span>}
+    </Button>)}
+  </div>;
+}
+
+export function PluginVaultPage({ model }: { model: VaultPages }) {
+  const { t } = useI18n();
+  const page = model.selected!;
+  const { mountRef, loading } = useEmbeddedPluginView({ viewId: page.viewId, version: page.version, slot: 'vault-page',
+    active: model.active, context: model.context, adapter: model.contributions, subscribeHidden, unavailable: model.fallback });
+  return <section className="flex min-h-0 flex-1 flex-col" aria-label={page.title} data-plugin-vault-page={page.key}>
+    <header className="app-no-drag flex h-12 shrink-0 items-center justify-between gap-3 border-b border-border px-4">
+      <div className="min-w-0"><h2 className="truncate text-sm font-medium">{page.title}</h2>
+        <p className="truncate text-xs text-muted-foreground">{page.pluginName} · {page.version}</p></div>
+      <Button variant="ghost" onClick={model.fallback}>{t('plugins.vault.back')}</Button>
+    </header>
+    <div ref={mountRef} className="relative min-h-0 flex-1 overflow-hidden" data-plugin-view-slot="vault-page">
+      {loading && <p role="status" className="p-4 text-sm text-muted-foreground">{t('plugins.vault.loading')}</p>}
+    </div>
+  </section>;
+}

components/settings/tabs/PluginPackageManager.tsx

@@ -28,7 +28,7 @@ export function PluginPackageDetails({ plugin }: { plugin: NetcattyInstalledPlug
       <dt className="text-muted-foreground">API</dt><dd>{manifest.engines.api}</dd>
       <dt className="text-muted-foreground">SHA-256</dt><dd className="break-all font-mono">{plugin.archiveSha256 ?? '-'}</dd>
     </dl>
-    <p className={!policy.browserOnly ? 'text-destructive' : 'text-muted-foreground'}>{t(`settings.plugins.manager.${runtimeLabel}`)}</p>
+    <p className={!policy.browserOnly && !policy.dataOnly ? 'text-destructive' : 'text-muted-foreground'}>{policy.dataOnly ? t('settings.plugins.manager.dataTheme') : t(`settings.plugins.manager.${runtimeLabel}`)}</p>
     <div className="space-y-2">
       <h4 className="font-medium">{t('settings.plugins.manager.permissions')}</h4>
       <p className="text-xs text-muted-foreground">{t('settings.plugins.manager.permissionNote')}</p>

components/settings/tabs/PluginPermissionPanel.tsx

@@ -56,7 +56,7 @@ export function PluginPermissionPanel({ pluginId, onChanged }: {
       pending.current = false; setBusy(false);
     }
   };
-  return <section className="space-y-3 border-t border-border/60 pt-4 text-sm" aria-label={t('settings.plugins.permissions.title')}>
+  return <section data-host-security-surface="" className="space-y-3 border-t border-border/60 pt-4 text-sm" aria-label={t('settings.plugins.permissions.title')}>
     <div className="flex flex-wrap items-center justify-between gap-2">
       <h4 className="font-medium">{t('settings.plugins.permissions.title')}</h4>
       <Button variant="ghost" size="sm" disabled={busy} onClick={() => void refresh()}>{t('settings.plugins.permissions.refresh')}</Button>

components/settings/tabs/PluginThemePicker.test.tsx

@@ -0,0 +1,230 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { JSDOM } from "jsdom";
+import type {
+  ThemePackCatalog,
+  ThemePackEntry,
+} from "@netcatty/plugin-contract";
+
+test("host theme picker previews without persistence, applies, restores, and cancels stale owners safely", async () => {
+  const dom = new JSDOM(
+    '<!doctype html><html><body><div id="root"></div></body></html>',
+    { url: "http://localhost", pretendToBeVisual: true },
+  );
+  const previous = new Map<string, PropertyDescriptor | undefined>();
+  for (const key of [
+    "window",
+    "document",
+    "navigator",
+    "HTMLElement",
+    "Element",
+    "Node",
+    "Event",
+    "MouseEvent",
+    "IS_REACT_ACT_ENVIRONMENT",
+  ]) {
+    previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key));
+    Object.defineProperty(globalThis, key, {
+      configurable: true,
+      writable: true,
+      value:
+        key === "IS_REACT_ACT_ENVIRONMENT"
+          ? true
+          : key === "window"
+            ? dom.window
+            : dom.window[key as keyof typeof dom.window],
+    });
+  }
+  const { default: React, act, useLayoutEffect } = await import("react");
+  const { createRoot } = await import("react-dom/client");
+  const { I18nProvider } = await import(
+    "../../../application/i18n/I18nProvider"
+  );
+  const { PluginThemePicker } = await import("./PluginThemePicker");
+  const { pluginThemeRegistry: registry } = await import(
+    "../../../infrastructure/config/pluginThemeRegistry"
+  );
+  const { usePluginThemeRevision } = await import(
+    "../../../application/state/usePluginThemeRuntime"
+  );
+  const { getUiThemeById } = await import(
+    "../../../infrastructure/config/uiThemes"
+  );
+  const { applyThemeTokens } = await import(
+    "../../../application/state/settingsStateDefaults"
+  );
+  const entry: ThemePackEntry = {
+    ref: {
+      pluginId: "com.example.theme",
+      themeId: "com.example.theme.forest",
+      version: "1.0.0",
+      digest: "a".repeat(64),
+      variant: "light",
+    },
+    label: "Forest",
+    pluginName: "Synthetic Theme",
+    dataOnly: true,
+    palette: { formatVersion: 1, base: "light", colors: { accent: "#166534" } },
+  };
+  let writes = 0,
+    restores = 0;
+  let catalog: ThemePackCatalog = {
+    selection: {
+      formatVersion: 1,
+      revision: registry.getCatalog().selection.revision + 1,
+      light: null,
+      dark: null,
+    },
+    entries: [entry],
+    diagnostics: [],
+  };
+  registry.setCatalog(catalog);
+  Object.assign(dom.window, {
+    netcatty: {
+      async applyPluginTheme(request: {
+        expectedRevision: number;
+        choice: ThemePackCatalog["selection"]["light"];
+      }) {
+        assert.equal(request.expectedRevision, catalog.selection.revision);
+        writes++;
+        catalog = {
+          ...catalog,
+          selection: {
+            ...catalog.selection,
+            revision: catalog.selection.revision + 1,
+            light: request.choice,
+          },
+        };
+        registry.setCatalog(catalog);
+        return catalog;
+      },
+    },
+  });
+  function Fixture() {
+    const revision = usePluginThemeRevision();
+    useLayoutEffect(
+      () =>
+        applyThemeTokens(
+          "light",
+          "light",
+          getUiThemeById("light", "snow").tokens,
+          "theme",
+          "",
+        ),
+      [revision],
+    );
+    return (
+      <I18nProvider locale="en">
+        <PluginThemePicker mode="light" onRestore={() => restores++} />
+      </I18nProvider>
+    );
+  }
+  const root = createRoot(document.getElementById("root")!);
+  const button = (label: string) =>
+    [...document.querySelectorAll<HTMLButtonElement>("button")].find(
+      (b) => b.textContent === label,
+    )!;
+  try {
+    await act(async () => root.render(<Fixture />));
+    const original =
+      document.documentElement.style.getPropertyValue("--primary");
+    await act(async () => {
+      const select = document.querySelector("select")!;
+      select.value = `${entry.ref.pluginId}/${entry.ref.themeId}`;
+      select.dispatchEvent(new Event("change", { bubbles: true }));
+    });
+    await act(async () => button("Preview").click());
+    assert.equal(writes, 0);
+    assert.equal(
+      getUiThemeById("light", "snow", false).tokens.primary,
+      original,
+      "local preview does not enter the global plugin view environment",
+    );
+    assert.notEqual(
+      document.documentElement.style.getPropertyValue("--primary"),
+      original,
+    );
+    assert.ok(
+      document.documentElement.hasAttribute("data-plugin-theme-active"),
+    );
+    assert.ok(
+      document.documentElement.style.getPropertyValue(
+        "--host-security-primary",
+      ),
+    );
+    await act(async () => button("Cancel preview").click());
+    assert.equal(
+      document.documentElement.style.getPropertyValue("--primary"),
+      original,
+    );
+    assert.equal(writes, 0);
+    await act(async () => {
+      button("Preview").click();
+      button("Apply").click();
+    });
+    assert.equal(writes, 1);
+    assert.equal(catalog.selection.light?.ref.themeId, entry.ref.themeId);
+    await act(async () => button("Restore default").click());
+    assert.equal(writes, 2);
+    assert.equal(restores, 1);
+    assert.equal(catalog.selection.light, null);
+    await act(async () => {
+      registry.startPreview("old-owner", entry);
+      registry.startPreview("new-owner", entry);
+      registry.cancelPreview("old-owner");
+    });
+    assert.notEqual(
+      document.documentElement.style.getPropertyValue("--primary"),
+      original,
+    );
+    await act(async () =>
+      registry.setCatalog({
+        ...catalog,
+        selection: {
+          ...catalog.selection,
+          revision: catalog.selection.revision + 1,
+        },
+        entries: [],
+      }),
+    );
+    assert.equal(
+      document.documentElement.style.getPropertyValue("--primary"),
+      original,
+      "package withdrawal cancels previews",
+    );
+    await act(async () =>
+      registry.setCatalog({
+        ...catalog,
+        selection: {
+          ...catalog.selection,
+          revision: catalog.selection.revision + 2,
+          light: { ref: entry.ref },
+        },
+        entries: [],
+      }),
+    );
+    assert.equal(getUiThemeById("light", "snow").id, "host-plugin-fallback");
+    await act(async () => registry.setHighContrast(true));
+    assert.equal(getUiThemeById("light", "snow").id, "host-high-contrast");
+  } finally {
+    await act(async () => {
+      root.unmount();
+      registry.setHighContrast(false);
+      registry.setCatalog({
+        ...catalog,
+        selection: {
+          formatVersion: 1,
+          revision: registry.getCatalog().selection.revision + 1,
+          light: null,
+          dark: null,
+        },
+        entries: [],
+      });
+    });
+    dom.window.close();
+    for (const [key, descriptor] of previous) {
+      if (descriptor) Object.defineProperty(globalThis, key, descriptor);
+      else Reflect.deleteProperty(globalThis, key);
+    }
+  }
+});

components/settings/tabs/PluginThemePicker.tsx

@@ -0,0 +1,166 @@
+import { useEffect, useId, useState } from "react";
+import { useI18n } from "../../../application/i18n/I18nProvider";
+import {
+  applyPluginThemeSelection,
+  usePluginThemeRevision,
+} from "../../../application/state/usePluginThemeRuntime";
+import { pluginThemeRegistry } from "../../../infrastructure/config/pluginThemeRegistry";
+import { Button } from "../../ui/button";
+
+export function PluginThemePicker({
+  mode,
+  onRestore,
+}: {
+  mode: "light" | "dark";
+  onRestore: () => void;
+}) {
+  const { t } = useI18n();
+  usePluginThemeRevision();
+  const owner = useId();
+  const [selected, setSelected] = useState(""),
+    [pending, setPending] = useState(false),
+    [error, setError] = useState("");
+  const catalog = pluginThemeRegistry.getCatalog();
+  const entries = catalog.entries.filter((e) => e.palette.base === mode);
+  const applied = catalog.selection[mode];
+  const appliedAvailable =
+    applied &&
+    entries.some(
+      (e) =>
+        e.ref.pluginId === applied.ref.pluginId &&
+        e.ref.themeId === applied.ref.themeId &&
+        e.ref.version === applied.ref.version &&
+        e.ref.digest === applied.ref.digest,
+    );
+  const entry = entries.find(
+    (e) => `${e.ref.pluginId}/${e.ref.themeId}` === selected,
+  );
+  useEffect(
+    () => () => pluginThemeRegistry.cancelPreview(owner),
+    [owner, mode],
+  );
+  async function apply(restore = false) {
+    if (pending || (!restore && !entry)) return;
+    setPending(true);
+    setError("");
+    try {
+      await applyPluginThemeSelection(
+        mode,
+        restore ? null : { ref: entry!.ref },
+      );
+      pluginThemeRegistry.cancelPreview(owner);
+      if (restore) {
+        setSelected("");
+        onRestore();
+      }
+    } catch (e) {
+      setError(
+        e instanceof Error ? e.message : t("settings.plugins.themes.failed"),
+      );
+    } finally {
+      setPending(false);
+    }
+  }
+  return (
+    <section
+      className="space-y-3 py-3"
+      aria-label={t("settings.plugins.themes.title")}
+    >
+      <div>
+        <h4 className="text-sm font-medium">
+          {t("settings.plugins.themes.title")}
+        </h4>
+        <p className="text-xs text-muted-foreground">
+          {t("settings.plugins.themes.description")}
+        </p>
+      </div>
+      {entries.length === 0 ? (
+        <p className="text-xs text-muted-foreground">
+          {t("settings.plugins.themes.empty")}
+        </p>
+      ) : (
+        <select
+          className="h-9 w-full rounded-md border border-input bg-background px-3 text-sm"
+          aria-label={t("settings.plugins.themes.choose")}
+          value={entry ? selected : ""}
+          disabled={pending}
+          onChange={(e) => {
+            pluginThemeRegistry.cancelPreview(owner);
+            setSelected(e.target.value);
+            setError("");
+          }}
+        >
+          <option value="">{t("settings.plugins.themes.choose")}</option>
+          {entries.map((e) => (
+            <option
+              key={`${e.ref.pluginId}/${e.ref.themeId}`}
+              value={`${e.ref.pluginId}/${e.ref.themeId}`}
+            >
+              {e.label} — {e.pluginName} {e.ref.version}
+            </option>
+          ))}
+        </select>
+      )}
+      {catalog.selection[mode] && (
+        <p className="text-xs text-muted-foreground">
+          {t(
+            appliedAvailable
+              ? "settings.plugins.themes.applied"
+              : "settings.plugins.themes.unavailable",
+          )}
+          : {catalog.selection[mode]!.ref.themeId} ·{" "}
+          {catalog.selection[mode]!.ref.version}
+        </p>
+      )}
+      <div className="flex flex-wrap gap-2">
+        <Button
+          size="sm"
+          variant="outline"
+          disabled={!entry || pending}
+          onClick={() => {
+            if (entry) pluginThemeRegistry.startPreview(owner, entry);
+          }}
+        >
+          {t("settings.plugins.themes.preview")}
+        </Button>
+        <Button
+          size="sm"
+          disabled={!entry || pending}
+          onClick={() => {
+            void apply();
+          }}
+        >
+          {t("settings.plugins.themes.apply")}
+        </Button>
+        <Button
+          size="sm"
+          variant="ghost"
+          disabled={pending}
+          onClick={() => pluginThemeRegistry.cancelPreview(owner)}
+        >
+          {t("settings.plugins.themes.cancel")}
+        </Button>
+        <Button
+          size="sm"
+          variant="outline"
+          disabled={pending}
+          onClick={() => {
+            void apply(true);
+          }}
+        >
+          {t("settings.plugins.themes.restore")}
+        </Button>
+      </div>
+      {catalog.diagnostics.length > 0 && (
+        <p className="text-xs text-muted-foreground">
+          {t("settings.plugins.themes.invalid")}
+        </p>
+      )}
+      {error && (
+        <p role="alert" className="text-xs text-destructive">
+          {error}
+        </p>
+      )}
+    </section>
+  );
+}

components/settings/tabs/SettingsAppearanceTab.tsx

@@ -1,3 +1,6 @@
+import { PluginThemePicker } from './PluginThemePicker';
+import { applyPluginThemeSelection, usePluginThemeRevision } from '../../../application/state/usePluginThemeRuntime';
+import { pluginThemeRegistry } from '../../../infrastructure/config/pluginThemeRegistry';
 import React, { memo, useCallback, useMemo, useState } from "react";
 import { applyCustomCssToDocument } from "../../../lib/customCss";
 import { DebouncedTextarea } from "../DebouncedTextarea";
@@ -70,6 +73,8 @@ function SettingsAppearanceTab(props: {
   setAppIconVariant: (variant: AppIconVariant) => void;
 }) {
   const { t } = useI18n();
+  usePluginThemeRevision();
+  const [pluginThemeError, setPluginThemeError] = useState('');
   const availableUIFonts = useAvailableUIFonts();
   // Note code fonts come from the monospace-only store (fontStore); the note
   // body font follows the UI font setting instead.
@@ -231,8 +236,12 @@ function SettingsAppearanceTab(props: {
   );
 
   const visibleUiThemes = resolvedTheme === "dark" ? DARK_UI_THEMES : LIGHT_UI_THEMES;
-  const visibleUiThemeId = resolvedTheme === "dark" ? darkUiThemeId : lightUiThemeId;
-  const setVisibleUiThemeId = resolvedTheme === "dark" ? setDarkUiThemeId : setLightUiThemeId;
+  const visibleUiThemeId = pluginThemeRegistry.isActive(resolvedTheme) ? "" : resolvedTheme === "dark" ? darkUiThemeId : lightUiThemeId;
+  const setVisibleUiThemeId = (id: string) => {
+    void applyPluginThemeSelection(resolvedTheme, null).then(() => {
+      (resolvedTheme === "dark" ? setDarkUiThemeId : setLightUiThemeId)(id);setPluginThemeError('');
+    }).catch((error: unknown) => setPluginThemeError(error instanceof Error ? error.message : t('settings.plugins.themes.failed')));
+  };
 
   return (
     <SettingsTabContent value="appearance">
@@ -339,6 +348,8 @@ function SettingsAppearanceTab(props: {
             {renderThemeSwatches(visibleUiThemes, visibleUiThemeId, setVisibleUiThemeId)}
           </div>
         </SettingsAnchor>
+        <PluginThemePicker mode={resolvedTheme} onRestore={() => (resolvedTheme === "dark" ? setDarkUiThemeId : setLightUiThemeId)(resolvedTheme === "dark" ? "midnight" : "snow")} />
+        {pluginThemeError && <p role="alert" className="text-xs text-destructive">{pluginThemeError}</p>}
         <SettingRow
           anchorId="appearance-accent-mode"
           label={t("settings.appearance.accentColor.mode")}

components/terminal/TerminalHostKeyVerification.tsx

@@ -30,7 +30,7 @@ export const TerminalHostKeyVerification: React.FC<TerminalHostKeyVerificationPr
     const Icon = isChanged ? AlertTriangle : Fingerprint;
 
     return (
-        <div className="space-y-3 animate-in fade-in-0 slide-in-from-bottom-1 duration-200">
+        <div data-host-security-surface="" className="space-y-3 animate-in fade-in-0 slide-in-from-bottom-1 duration-200">
             <div
                 className={cn(
                     "rounded-xl border px-3 py-2.5",

components/terminal/TerminalToolbar.tsx

@@ -44,6 +44,7 @@ import { collectOwnedPluginMenus, comparePluginMenus, usePluginContributions } f
 import { buildTerminalPluginContributionContext } from '../../application/state/pluginContributionContexts';
 import { PluginContributionIcon } from '../plugins/PluginContributionIcon';
 import { isPluginHostProtocol } from '../../domain/pluginConnection';
+import { PluginTerminalSidebarLauncher } from '../plugins/PluginTerminalSidebar';
 
 export const TERMINAL_TOOLBAR_ITEM_IDS = [
   'highlight',
@@ -1158,6 +1159,7 @@ export const TerminalToolbar: React.FC<TerminalToolbarProps> = ({
         )}
         </ToolbarCustomizeContextMenu>
 
+        {!compactToolbar && <PluginTerminalSidebarLauncher sessionId={sessionId} />}
         {pluginToolbarMenus.map((menu) => (
         <Tooltip key={menu.id}>
           <TooltipTrigger asChild>

components/terminalLayer/TerminalLayerSidePanelSection.tsx

@@ -9,7 +9,7 @@ import React, { memo, useCallback, useEffect, useLayoutEffect, useMemo, useRef,
 import { createPortal } from 'react-dom';
 import * as SelectPrimitive from '@radix-ui/react-select';
 
-import { useActiveTabId } from '../../application/state/activeTabStore';
+import { activeTabStore, useActiveTabId } from '../../application/state/activeTabStore';
 import {
   getSidePanelLiveSnapshot,
   subscribeSidePanelLiveSnapshot,
@@ -48,6 +48,7 @@ import {
   MAX_SIDE_PANEL_PANES,
   canSplitSidePanelPaneAtSize,
   collectSidePanelPanes,
+  isPluginSidePanelTool,
   getFocusedSidePanelPane,
   getSidePanelNodeMinimumPixels,
   getSidePanelSplitResizeBounds,
@@ -60,7 +61,10 @@ import {
   type SidePanelSplitNode,
 } from '../../domain/sidePanelLayout';
 import { terminalLayerSidePanelStableCtxEqual } from './terminalLayerViewMemo';
-import { SidePanelMountedContent } from './terminalLayerSidePanelSlots';
+import { PersistentSidePanelPortal, SidePanelMountedContent } from './terminalLayerSidePanelSlots';
+import { usePluginTerminalSidebar } from '../../application/state/usePluginTerminalSidebar';
+import { PluginTerminalSidebarPageHost } from '../plugins/PluginTerminalSidebar';
+import { PluginContributionIcon } from '../plugins/PluginContributionIcon';
 import { getPaneMagnificationShortcutLabel } from '../../domain/paneMagnification';
 
 const MemoizedSidePanelMountedContent = memo(
@@ -358,7 +362,7 @@ function SidePanelSplitView({
   );
 }
 
-function SidePanelLayoutTree({
+export function SidePanelLayoutTree({
   node,
   layout,
   paneCount,
@@ -568,6 +572,9 @@ function hasMountedSidePanelContent(ctx: SidePanelContext): boolean {
     && Array.from((sidePanelOpenTabs as Map<string, SidePanelTab>).values()).includes('history');
   const anyNotesOpen = sidePanelOpenTabs instanceof Map
     && Array.from((sidePanelOpenTabs as Map<string, SidePanelTab>).values()).includes('notes');
+  const anyPluginOpen = ctx.sidePanelLayouts instanceof Map
+    && [...(ctx.sidePanelLayouts as Map<string, SidePanelLayout>).values()]
+      .some((layout) => collectSidePanelPanes(layout.root).some((pane) => isPluginSidePanelTool(pane.tool)));
 
   return !(
     browserMountedTabIds.length === 0
@@ -579,10 +586,16 @@ function hasMountedSidePanelContent(ctx: SidePanelContext): boolean {
     && themeMountedTabIds.length === 0
     && !anyHistoryOpen
     && !anyNotesOpen
+    && !anyPluginOpen
   );
 }
 
 function TerminalLayerSidePanelSectionInner({ ctx }: { ctx: SidePanelContext }) {
+  const pluginSidebar = usePluginTerminalSidebar({ layouts: ctx.sidePanelLayouts ?? new Map(),
+    getSession: ctx.getActiveTerminalSessionId ?? (() => null),
+    isTerminalTab: (tabId) => (ctx.sessions ?? []).some((session: { id: string }) => session.id === tabId) || !!ctx.workspaceById?.has(tabId),
+    select: (tool) => ctx.handleSwitchSidePanelTab?.(tool),
+    withdraw: (tabId, paneId, tool) => ctx.handleWithdrawPluginSidebarPane?.(tabId, paneId, tool) });
   if (!hasMountedSidePanelContent(ctx)) {
     // Keep AI scope maintenance alive even with zero mounted tool panels so
     // merge/dissolve handoff still runs when the user closed AI before the
@@ -604,7 +617,7 @@ function TerminalLayerSidePanelSectionInner({ ctx }: { ctx: SidePanelContext })
       </AISidePanelStateRoot>
     );
   }
-  return <TerminalLayerSidePanelInner ctx={ctx} />;
+  return <TerminalLayerSidePanelInner ctx={ctx} pluginSidebar={pluginSidebar} />;
 }
 
 /** Skip chrome rebuilds when only live/workspace-focus ticks change. */
@@ -614,7 +627,7 @@ export const TerminalLayerSidePanelSection = memo(
 );
 TerminalLayerSidePanelSection.displayName = 'TerminalLayerSidePanelSection';
 
-function TerminalLayerSidePanelInner({ ctx }: { ctx: SidePanelContext }) {
+function TerminalLayerSidePanelInner({ ctx, pluginSidebar }: { ctx: SidePanelContext; pluginSidebar: ReturnType<typeof usePluginTerminalSidebar> }) {
   const activeTabId = useActiveTabId();
   const sidePanelOpenTabs = ctx.sidePanelOpenTabs as Map<string, SidePanelTab>;
   const sidePanelLayouts = ctx.sidePanelLayouts as Map<string, SidePanelLayout>;
@@ -630,6 +643,7 @@ function TerminalLayerSidePanelInner({ ctx }: { ctx: SidePanelContext }) {
     handleOpenAI,
     handleOpenHistory,
     handleOpenNotes,
+    handleSwitchSidePanelTab,
     handleOpenBrowser,
     handleOpenScripts,
     handleOpenSystem,
@@ -1046,6 +1060,9 @@ function TerminalLayerSidePanelInner({ ctx }: { ctx: SidePanelContext }) {
     { id: 'system' as const, label: t('terminal.layer.system'), icon: <Activity size={15} />, onClick: handleOpenSystem },
     { id: 'notes' as const, label: t('terminal.layer.notes'), icon: <NotebookText size={15} />, onClick: handleOpenNotes },
     { id: 'ai' as const, label: t('terminal.layer.aiChat'), icon: <MessageSquare size={15} />, onClick: handleOpenAI },
+    ...pluginSidebar.pages.map((page) => ({ id: page.tool, label: `${page.title} · ${page.pluginName}`,
+      icon: <PluginContributionIcon pluginId={page.pluginId} icon={page.icon} size={15} />,
+      onClick: () => handleSwitchSidePanelTab?.(page.tool) })),
   ], [
     handleOpenAI,
     handleOpenHistory,
@@ -1056,6 +1073,8 @@ function TerminalLayerSidePanelInner({ ctx }: { ctx: SidePanelContext }) {
     handleOpenTheme,
     handleToggleSftpFromBar,
     t,
+    handleSwitchSidePanelTab,
+    pluginSidebar.pages,
   ]);
   const sidePanelTabItemById = useMemo(
     () => new Map(sidePanelTabItems.map((item) => [item.id, item])),
@@ -1491,6 +1510,19 @@ function TerminalLayerSidePanelInner({ ctx }: { ctx: SidePanelContext }) {
             paneHosts={panePortalHosts}
             parkingHost={parkingHost}
           />
+          {activeTabId && pluginSidebar.sessionId && activeSidePanelPanes.map((pane) => {
+            const page = pluginSidebar.pages.find((item) => item.tool === pane.tool);
+            const target = panePortalHosts.get(pane.tool) ?? parkingHost;
+            if (!page || !target) return null;
+            const sessionId = pluginSidebar.sessionId!;
+            return <PersistentSidePanelPortal key={`${activeTabId}:${pane.id}:${sessionId}`} portalKey={`plugin-${pane.id}`} target={target}>
+              <PluginTerminalSidebarPageHost page={page} tabId={activeTabId} sessionId={sessionId}
+                focusOnReveal={activeSidePanelLayout?.focusedPaneId === pane.id}
+                adapter={pluginSidebar.contributions} getSession={ctx.getActiveTerminalSessionId}
+                unavailable={() => ctx.handleWithdrawPluginSidebarPane?.(activeTabId, pane.id, page.tool)}
+                focused={() => { if (activeTabStore.getActiveTabId() === activeTabId) ctx.handleFocusSidePanelPane?.(pane.id); }} />
+            </PersistentSidePanelPortal>;
+          })}
         </div>
       </div>
     </div>

components/terminalLayer/TerminalLayerTabBridge.test.ts

@@ -32,6 +32,13 @@ test('terminal layer bridge passes vault open callbacks into the side panel cont
   assert.match(source, /onOpenVaultSectionFromChat: s\.onOpenVaultSectionFromChat/);
 });
 
+test('production terminal layer context forwards extension sidebar owner and pane callbacks', () => {
+  const contextProjection = source.slice(source.indexOf('const ctx = useMemo('));
+  for (const callback of ['getActiveTerminalSessionId', 'handleSwitchSidePanelTab', 'handleWithdrawPluginSidebarPane']) {
+    assert.match(contextProjection, new RegExp(`${callback}: s\\.${callback}\\b`));
+  }
+});
+
 test('terminal layer bridge updates side panel live state after render', () => {
   assert.match(source, /const sidePanelLiveSnapshot = useMemo<SidePanelLiveSnapshot>/);
   assert.match(

components/terminalLayer/TerminalLayerTabBridge.tsx

@@ -489,6 +489,9 @@ export function TerminalLayerTabBridge({ stableRef }: { stableRef: StableRef })
     handleFontWeightResetForFocusedSession: themeState.handleFontWeightResetForFocusedSession,
     handleOpenAI: s.handleOpenAI,
     handleOpenNotes: s.handleOpenNotes,
+    getActiveTerminalSessionId: s.getActiveTerminalSessionId,
+    handleSwitchSidePanelTab: s.handleSwitchSidePanelTab,
+    handleWithdrawPluginSidebarPane: s.handleWithdrawPluginSidebarPane,
     handleOpenBrowser: s.handleOpenBrowser,
     handleOpenSystem: s.handleOpenSystem,
     handleOpenHistory: s.handleOpenHistory,

components/terminalLayer/TerminalLayerView.tsx

@@ -7,8 +7,9 @@ import { TerminalLayerWorkspaceSection } from './TerminalLayerWorkspaceSection';
 import { terminalLayerViewCtxEqual } from './terminalLayerViewMemo';
 import { useTerminalHostTreeLayoutWidth } from '../../application/state/terminalHostTreeStore';
 import { resolveTerminalLayerSurfaceStyle } from '../terminalPaneVisibility';
+import type { PluginSidebarHostActions } from '../../application/state/usePluginTerminalSidebar';
 
-type TerminalLayerViewContext = Record<string, any>;
+type TerminalLayerViewContext = Record<string, any> & PluginSidebarHostActions;
 
 function TerminalLayerViewInner({ ctx }: { ctx: TerminalLayerViewContext }) {
   const hostTreeLayoutWidth = useTerminalHostTreeLayoutWidth();

components/terminalLayer/terminalLayerSidePanelSlots.tsx

@@ -693,7 +693,7 @@ export function movePersistentPortalNode(
   }
 }
 
-function PersistentSidePanelPortal({
+export function PersistentSidePanelPortal({
   portalKey,
   target,
   children,

components/terminalLayer/terminalLayerViewMemo.ts

@@ -316,6 +316,9 @@ const SIDE_PANEL_STABLE_CTX_KEYS = [
   'handleOpenTheme',
   'handleOpenAI',
   'handleOpenNotes',
+  'getActiveTerminalSessionId',
+  'handleSwitchSidePanelTab',
+  'handleWithdrawPluginSidebarPane',
   'handleOpenBrowser',
   'handleBackFromNotes',
   'handleOpenHostFromNotes',

components/vault/VaultViewLayout.tsx

@@ -29,6 +29,7 @@ import { LazyLoadBoundary } from "../ui/lazy-load-boundary";
 import { toast } from "../ui/toast";
 import { AppWordmark } from "../AppWordmark";
 import { openHostBrowser } from "../../application/hostBrowser";
+import { PluginVaultNavigation, PluginVaultPage } from '../plugins/PluginVaultPages';
 
 type VaultViewLayoutContext = Record<string, any>;
 
@@ -156,6 +157,7 @@ export function VaultViewLayout({ ctx }: { ctx: VaultViewLayoutContext }) {
     ContextMenuTrigger,
     Copy,
     currentSection,
+    pluginVault,
     customGroups,
     deleteGroupPaths,
     deleteGroupWithHosts,
@@ -595,12 +597,13 @@ export function VaultViewLayout({ ctx }: { ctx: VaultViewLayoutContext }) {
           </div>
 
           <div
-            className={cn("space-y-1", sidebarCollapsed ? "px-1.5" : "px-2.5")}
+            className={cn("min-h-0 flex-1 overflow-y-auto space-y-1", sidebarCollapsed ? "px-1.5" : "px-2.5")}
           >
             <Tooltip>
               <TooltipTrigger asChild>
                 <RippleButton
                   variant={currentSection === "hosts" ? "secondary" : "ghost"}
+                  data-plugin-vault-fallback
                   className={cn(
                     "w-full h-10",
                     sidebarCollapsed
@@ -805,11 +808,12 @@ export function VaultViewLayout({ ctx }: { ctx: VaultViewLayoutContext }) {
                 </TooltipContent>
               )}
             </Tooltip>
+            {pluginVault && <PluginVaultNavigation model={pluginVault} collapsed={sidebarCollapsed} />}
           </div>
 
           <div
             className={cn(
-              "mt-auto pb-4 space-y-2",
+              "mt-auto shrink-0 pb-4 space-y-2",
               sidebarCollapsed ? "px-1.5" : "px-2.5",
             )}
           >
@@ -864,6 +868,7 @@ export function VaultViewLayout({ ctx }: { ctx: VaultViewLayoutContext }) {
             className="flex-1 min-w-0 flex flex-col min-h-0 relative"
             data-section="vault-main"
           >
+            {pluginVault?.selected && <PluginVaultPage key={pluginVault.selected.key} model={pluginVault} />}
             <VaultPageHeader
               className={cn(!isHostsSectionActive && "hidden")}
               dataSection="vault-hosts-header"

docs/plugin-platform/capability-coverage.md

@@ -17,7 +17,7 @@ mean complete. Existing APIs remain available.
 | Terminal providers | Decorations, links, completion, snapshots through provider requests | Session change delivery follows prior provider request and non-once grant | Preserve providers. Standalone selected-session watch planned | Hostnames, session state, endpoint identity | Host-selected session, runtime identity | Session-close and revoke cleanup, bounded event rate | Existing provider tests. Ordinary views cannot independently subscribe today |
 | Current context and host picker | Host context keys are boolean state | `vault.metadata` enumeration is not generic SDK | Selected host/session DTO from an explicit whitelist | Labels and endpoint metadata are sensitive | Host-owned user-action context, selected host/session | TTL, runtime and session invalidation, redacted audit | Planned. Never reuse agent `sanitizeHostForAgent` as plugin DTO |
 | Terminal selection and input draft | Provider-supplied snapshots, completion suggestions | No explicit selection-share or draft API | User shares selection, plugin proposes a visible editable draft | Terminal plaintext, accidental execution | Host action token plus exact live session/endpoint | Single-use token, size cap, no plaintext audit, active identity before commit | Planned. Reject Enter/control characters for draft insertion. No full history or direct shell |
-| Native interactions and clipboard | Native permission dialogs; new browser SDK host choice/input and explicit copy/share workflow | Progress/toast remain unimplemented | Host-owned prompts, two-phase clipboard snapshot/share, exact copy preview | Clipboard and input may contain secrets; UI discloses granted network capability; prompt spam | `ui.interact`, clipboard direction, host-signed window/runtime/version/phase/TTL action | Admission before permission prompt, byte/rate/concurrency limits, lock/blur/close/revoke cleanup, active guard, content-free audit | [Host interaction slice](./host-interactions.md) implemented and synthetic-tested; native acceptance/review/CI pending. Progress/toast still planned. No background reads or trusted plugin `userGesture` boolean |
+| Native interactions and clipboard | Native permission dialogs; new browser SDK host choice/input and explicit copy/share workflow | Progress/toast remain unimplemented | Host-owned prompts, two-phase clipboard snapshot/share, exact copy preview | Clipboard and input may contain secrets; UI discloses granted network capability; prompt spam | `ui.interact`, clipboard direction, host-signed window/runtime/version/phase/TTL action | Admission before permission prompt, byte/rate/concurrency limits, lock/blur/close/revoke cleanup, active guard, content-free audit | [Host interaction slice](./host-interactions.md) implemented and synthetic-tested. 8e4dd0c exact test/packaging CI and independent delta review passed. Parent native compose and explicit Preview/Share/copy succeeded; a separately approved 0.1.1 compose ran about 86 seconds, beyond the old 30-second deadline and within the declared 180-second budget, with no fresh command-timeout error. All five permissions were Once; cleanup is parent-owned. New navigation slices retain separate acceptance gates. Progress/toast still planned. No background reads or trusted plugin `userGesture` boolean |
 | Local filesystem | Read file, stat, overwrite existing regular file | Directory listing lacks same-handle native adapter | Keep current boundary, evaluate file picker handles | Arbitrary local file content and writes | Canonical exact path or selected file handle | Inode checks, no symlink alias, bounded bytes, active runtime | Existing filesystem tests. Directory enumeration and new arbitrary-path creation deferred until portable safe native adapter exists |
 | SFTP and remote files | No generic plugin API | `sftp.read` and `sftp.write` enumerated only | Host-selected session/path/mode/TTL handles, read and explicit save/upload | Remote secrets and destructive overwrite | Live endpoint identity, exact path, read/write split | Cancel streams, byte quota, overwrite confirmation, close/revoke cleanup | Batch 2 planned. Never forward arbitrary MCP catalog or session ID alone |
 | Editor and Notes | No plugin document API | No versioned snapshot or edit preview | Explicit snapshot and versioned proposed edit | Document secrets, lost updates, executable files | Selected document plus revision and action token | Version conflict check, preview, bounded bytes, revocation | Planned evaluation after shared action context. No unattended edits |
@@ -27,12 +27,12 @@ mean complete. Existing APIs remain available.
 | Vault and keychain | Credential references and import preview/commit | Metadata/write enums do not grant a generic Vault SDK | Only user-selected whitelist DTOs and drafts | Notes, environmentVariables, startupCommand, keys and credentials | Selected object plus field/direction | Explicit preview, identity checks, redacted audit | Full Vault export and secret reads deferred indefinitely. No agent field-exclusion DTO reuse |
 | System manager and Docker | No plugin system API | Agent/MCP adapters are separate authority | Typed read-only summaries excluding args/env/inspect | Process command lines and Docker inspect can expose secrets | Selected live session and summary kind | Bounded result, endpoint identity, cancellation | Planned evaluation. Arbitrary process/inspect forwarding deferred |
 | Port forwarding | No generic plugin API | Existing agent start is write-sensitive | Selected rule status and open host form | Rule endpoints and local exposure | Selected rule plus host action | Bounded DTO, session close and revoke | Planned evaluation. Direct start deferred until binding/listener approval design |
-| Themes, settings, appearance, i18n | Terminal theme/background Providers, isolated view CSS, scoped settings and environment updates | No host global theme contribution. Personal customCSS is not plugin authority | Accepted ThemePack stage: static palette registry, selector, local preview, revision-safe apply/cancel/reset, terminal linkage | Unreadable palettes and misleading security UI. Nineteen UiThemeTokens fields are not independent: accent derives primary/ring/foregrounds | User explicitly selects a theme; static contribution enablement separate from code permissions | Immutable version/hash, bounded JSON, contrast/security-surface gates, preview owner/revision and safe fallback | Planned independent implementation after current controlled workflow/navigation. No arbitrary DOM/CSS, remote assets, layout replacement or security UI customization |
+| Themes, settings, appearance, i18n | Terminal theme/background Providers, isolated view CSS, scoped settings and environment updates | No host global theme contribution. Personal customCSS is not plugin authority | Accepted ThemePack stage: static palette registry, selector, local preview, revision-safe apply/cancel/reset, terminal linkage | Unreadable palettes and misleading security UI. Nineteen UiThemeTokens fields are not independent: accent derives primary/ring/foregrounds | User explicitly selects a theme; static contribution enablement separate from code permissions | Immutable version/hash, bounded JSON, contrast/security-surface gates, preview owner/revision and safe fallback | First host color layer implemented; [contract/lifecycle/evidence](./theme-packs.md). Exact-SHA CI, independent review and native acceptance pending. Static terminal linkage not yet accepted; no arbitrary DOM/CSS, remote assets, layout replacement or security UI customization |
 | Transfer center | Host transfer queue exists, no plugin entry | No ownership-bound task API | Observe and cancel only plugin-created tasks | Paths and host endpoints reveal user data. Cancel may leave partial files | Own transfer handle plus source/destination authority | Shared backpressure, cancel/close cleanup, honest partial status | Planned with batch 2. Do not broadcast or cancel other tasks |
 | AI, MCP, automation | Host agent catalog and harness exist separately | No generic plugin AI or tool forwarding | Selection-to-proposal workflow through the same controlled primitives | Content disclosure, account authority and model cost | Explicit content sharing plus service origin/budget | No inherited history, tools, account, or hidden cron | Controlled workflow planned. Generic host AI and visible schedules deferred to distinct product decision |
 | Known hosts, app lock and global security | Host security management UI | No plugin management API | Future allowlisted security-page navigation | Host-key trust, unlock, keys and security policy affect all sessions | Host navigation action only | No mutation or sensitive DTO | Security policy mutation, private-key reads, auto-trust and unlocking deferred indefinitely |
 | Plugin blob/cache | Local KV exists | No exclusive blob cache | Evaluate bounded plugin-owned cache when a real workflow needs it | Disk growth and lifecycle ambiguity | Plugin namespace, no arbitrary path | Size quota, eviction and uninstall policy required | Deferred until a concrete larger-than-KV workflow establishes value and retention policy |
-| Vault and terminal navigation | `tab` mounts a sandbox page through TopTabs/QuickSwitcher; aside/panel are overlays | No Vault subpage registry or terminal side-panel plugin tool. `settings` is a detail entry, not a new settings category | Accepted independent slice: host-owned namespaced Vault pages in an Extensions group, mounted in the Vault content area through existing ViewHost; then terminal pane/split pages for the selected session | Navigation cannot disclose session contents or replace built-in/security navigation | Declared page contribution plus host selection. Content reads have independent permissions | Host order/when/focus, cancellation of late open, view cleanup on hide/update/disable/uninstall, safe invalid-link fallback | Planned after host interaction/selected-context workflow. A button that merely opens a top tab does not satisfy Vault-page acceptance. No arbitrary router/DOM API |
+| Vault and terminal navigation | `tab` mounts a sandbox page through TopTabs/QuickSwitcher; aside/panel are overlays | No Vault subpage registry or terminal side-panel plugin tool. `settings` is a detail entry, not a new settings category | Accepted independent slice: host-owned namespaced Vault pages in an Extensions group, mounted in the Vault content area through existing ViewHost; then terminal pane/split pages for the selected session | Navigation cannot disclose session contents or replace built-in/security navigation | Declared page contribution plus host selection. Content reads have independent permissions | Host order/when/focus, cancellation of late open, view cleanup on hide/update/disable/uninstall, safe invalid-link fallback | [Vault page slice](./vault-pages.md) implemented and synthetic-tested: actual Vault content slot, private Scratchpad, catalog withdrawal, host occlusion, reserved-open cancellation, owner/crash/lock cleanup. Exact CI/independent/native acceptance pending. [Terminal sidebar slice](./terminal-sidebar.md) also implemented with actual pane/split mounting, owner focus and session-change cleanup; no automatic session data. Exact CI/independent/native acceptance pending for the new stack. No arbitrary router/DOM API |
 | Distribution and runtimes | Browser-only public catalog, immutable packages, advanced developer gate | Signing/trust and release remain separate phase | Retain existing boundary | Package execution and publisher trust | Pinned catalog selection, hash, engine/features | Existing install transaction, quarantine and cleanup | No merge/release. Do not extend to arbitrary Node, IPC, shell, or global capabilities |
 
 ## Delivery order and stopping rule
@@ -83,3 +83,84 @@ Baseline code references: `electron/plugins/hostService.cjs`,
 implementations under `electron/capabilities/catalog/` are reference material,
 not plugin authority. `infrastructure/ai/vaultAgentBridgeClient.ts` is not a
 plugin DTO sanitizer.
+
+## Navigation slice checkpoint
+
+The Vault stage adds `views.vault-pages`, the `vault-page` location, and the
+existing `views` permission. It grants no Vault/session data. The ordinary
+browser Scratchpad example uses only its own bounded view-state API and
+explicit user input. It is not a Notes API or automatic sync feature.
+
+The independent integration base includes #3956 UI polish and #3960 d4ca fixes;
+frozen evidence heads and prior PR bases are unchanged. Related UI changes in
+this stage are limited to VaultView/VaultViewLayout, new independent plugin
+components/hooks, and localized strings. PluginMarketplace/PluginPackageManager
+layouts are not rewritten. Native acceptance belongs to the parent with a new
+fixture-specific own-views approval. Sidebar, ThemePack, selected context and
+SFTP remain unfinished; this checkpoint is not overall completion.
+
+## Terminal sidebar checkpoint
+
+`views.terminal-sidebar` exposes one more existing sandbox view placement,
+using only the existing own-views permission. The host owns navigation,
+selection, split/close and focus. Its context is a surface string only; no
+terminal DTO or resource authority is implied. The Session Scratchpad fixture
+uses explicitly typed synthetic text and its own view state.
+
+This stage builds on ordinary merges containing #3960 8e4dd0c and the #3971
+stale-layout callback fix. Prior QA heads and PR bases are not rewritten. The
+ThemePack implementation, selected-context/drafts and file handles remain
+unfinished; parent review/native gates still apply to each delivered head.
+
+## Color-pack and remaining workflow checkpoint
+
+The first [ThemePack color layer](./theme-packs.md) now has an implemented host
+catalog, data-only admission, Appearance selector, local preview, revision-safe
+application/reset, missing-version fallback and host security palette boundary.
+It is not native-accepted until the new exact head is independently reviewed,
+built by CI and exercised through normal Settings. Terminal palette linkage is
+not accepted by this contract yet, so a declared but ignored linkage cannot be
+counted as coverage. Font/density/icon/background packs remain separate product
+and accessibility decisions, rather than arbitrary CSS permissions.
+
+Parent native evidence for sidebar `a8adeb86` now covers the original Local
+Terminal blocker, own-views Once, save, magnify/restore, a split with empty Notes,
+and side/bottom docking. `733f44c` adds only the production bridge projection
+regression. The older `0c097a1` CI run `40308057623` remains **failed and
+unattributed**: 9447 top-level TAP results are `ok`, the aggregate footer is
+missing and the process exits 1. A newer passing run does not change that record.
+The native Vault success retains its original `0c097a1` evidence label.
+
+The next implementation stages are bounded by useful workflows:
+
+1. **Selected terminal sharing and drafts (A).** Reuse host-signed action
+   contexts for an explicit selection preview/share, then let the plugin submit
+   a bounded input draft to the host compose surface. No Enter, raw PTY, history
+   enumeration or background terminal listener. First add a host-selected
+   session handle with a minimal from-scratch DTO and independent lifecycle
+   watch; navigation alone grants no content. Bind handles to actual session and
+   connection identity, runtime/version, owner, mode and TTL. Cover cancel,
+   reconnect, close, revoke and late draft results with synthetic terminals.
+2. **Selected file conversion/transfer (A).** The host picker issues read or
+   explicit-destination write handles. Start with one file, stat/read and saveAs
+   or upload, not recursive traversal or arbitrary paths. Require destination
+   preview/overwrite confirmation, byte/concurrency limits, cancellation,
+   session/endpoint identity and final active checks. Observe/cancel only the
+   plugin's own transfer. Real native SFTP targets require parent-coordinated
+   concrete approval; local tests use isolated fixtures.
+3. **Versioned document proposals (selected B).** Reuse snapshot/handle and host
+   review primitives for one explicitly shared editor document or Note. Apply
+   only an expected-version patch to its buffer after a visible diff; saving a
+   remote file remains a separate file operation. Reuse the draft path for a
+   selected snippet or new snippet template; do not run scripts or add onConnect
+   bindings. Cover edits after snapshot, detached ownership, closure and revoke.
+4. **Final reassessment.** Recheck the matrix by actual workflow and eight gates.
+   Read-only system aggregates, selected port-rule status and bounded navigation
+   may be added only where the shared primitives leave a concrete useful gap.
+   Full process arguments/env/inspect, tunnel start, arbitrary AI/MCP tools,
+   background jobs, general KV sync and raw high-privilege access remain deferred
+   or retained boundaries. Do not invent new C work to prolong the task.
+
+These stages remain unfinished work, not API-name coverage. Exact schemas and
+ordering will follow the existing brokers/adapters rather than a parallel RPC
+stack or one namespace per product module.

docs/plugin-platform/contract-and-sdk.md

@@ -630,3 +630,13 @@ negotiated API version and runtime initialization uses and verifies that exact
 version. Host version bounds remain independently enforced; unknown required
 features still fail closed. No old manifest is rewritten and no permission grant
 is migrated by this revision.
+
+## Declarative host color contributions
+
+`appearance.theme-packs` adds `contributes.themes` and generated palette/reference
+schemas. A pure package uses `main: { "data": "theme" }`, contributes only themes
+and omits permissions/activation/companions. It has no executable runtime. Normal
+admission accepts this data-only form alongside browser-only code packages; Node
+and arbitrary IPC remain advanced/unsupported public boundaries. Selection is a
+trusted host Appearance action, not an SDK setter or `appearance.write` grant.
+See [Theme packs](./theme-packs.md) for limits, preview, persistence and fallback.

docs/plugin-platform/isolated-runtime.md

@@ -300,3 +300,8 @@ installs plugins but fails to start them outside the repository checkout.
 separate `npm run test:plugin-runtime:electron` smoke launches both a real
 sandboxed BrowserWindow plugin and a real utilityProcess plugin, verifies
 bidirectional storage RPC, and checks the recorded runtime ownership.
+
+Static `appearance.theme-packs` packages are an explicit non-executable admission
+form: `main.data = "theme"`, theme-only contributions and no permissions,
+activation events or companions. The runtime supervisor never starts them. This
+exception does not admit Node code or arbitrary host access in normal Settings.

docs/plugin-platform/terminal-sharing-wip.md

@@ -0,0 +1,51 @@
+# Selected terminal sharing — implementation WIP
+
+Base: ThemePack `f868221b5f11810802f929369ac8eee46166079a`.
+Branch: `feat/plugin-terminal-sharing`. This is saved unfinished source, not an
+accepted API or an installable/native-tested workflow. Do not merge or release.
+
+Implemented source so far:
+
+- Canonical optional action-only `terminal.selection.read`, feature
+  `terminal.selection-sharing`, bounded result and host-target schemas; SDK
+  `context.terminals.shareSelection()` and runtime forwarding through the
+  existing `ui.interact` broker. No independent parallel RPC stack.
+- Main-only worker/session generation and window-owner binding accessor; no
+  endpoint or Host DTO returned to plugins.
+- Host target/handle authority, opaque signed short-lived receipts, capacity,
+  expiry and lifecycle hooks; no selected text stored in the authority.
+- Broker admission binding to the selected resource before a once-only grant,
+  signed Preview/Share phases, fixed audit metadata and teardown integration.
+- Trusted app-only selected-target setter, not a plugin API. No database,
+  installation/source/cache identity or private-storage schema changes.
+
+Still missing, and required before this counts as working:
+
+1. Trusted renderer target publication for the real active terminal/workspace;
+   actual bounded selection reader registered by the terminal surface. Read
+   only on Preview, from a visible connected terminal, never through Agent/MCP
+   history/context readers; refuse sensitive input, empty or oversized selection.
+2. Host dialog Preview response and explicit Share rendering, failure states,
+   exact resource/selection consistency and global lifecycle verification.
+3. Canonical/SDK/broker/authority/real-worker/renderer normal and boundary tests,
+   generated-contract and compatibility review (including optional-only
+   declaration semantics), quotas, owner/reconnect/close/revoke/late-result cases.
+4. Useful ordinary-browser synthetic example, fixture ID/hash/precise permissions,
+   build/CI, independent review/fix/review and parent-owned native acceptance.
+5. Separate input-draft layer: reuse the actual compose control without inheriting
+   broadcast targets, overwriting an existing draft silently, writing PTY bytes
+   or sending Enter. Require a separately approved target-bound draft action and
+   final active identity check. No input-proposal method/permission is delivered
+   by this WIP.
+
+Known integration constraints:
+
+- The market source-binding task owns installation, cache, authorization/private
+  storage identity and associated database schema. Coordinate before touching
+  those locations; runtime/assertActive identity must remain host-owned.
+- Keep the ThemePack security-color delta in its own branch/head. Incorporate
+  the eventually accepted head with a normal integration merge, not by rewriting
+  frozen evidence.
+- The user allows simplification of unreleased plugin historical data/protocols;
+  do not add legacy migration layers. Do not remove unrelated host/input data
+  migrations or weaken the sandbox.

docs/plugin-platform/terminal-sidebar.md

@@ -0,0 +1,74 @@
+# Terminal sidebar pages
+
+The `terminal-sidebar` view location requires `views.terminal-sidebar` and the
+existing `views` permission. This adds navigation and plugin-owned content to
+the existing terminal pane/split system. It is not a session-data capability,
+Provider subscription, terminal history reader or command execution API.
+
+## Host-owned navigation
+
+An Extension pages menu in the normal terminal toolbar lists visible pages
+with their plugin source. Selecting one switches the existing focused pane;
+selecting an already-open tool focuses that pane. Existing split menus include
+the same contributions and enforce unique tools and the eight-pane limit.
+Host-generated `plugin-view:<namespaced-view-id>` keys cannot replace built-in
+tools. Declared order and ID determine listing order; existing host docking,
+split resizing, magnification and close controls remain authoritative.
+
+The manager's internal Open event can select a page only when an open terminal
+is already selected. Otherwise the host asks the user to select a terminal; it
+does not connect or open a saved host. Launcher events target the session from
+the actual host terminal toolbar and are rechecked against current selection.
+These are internal host UI events, not public SDK router methods or trusted
+plugin `userGesture` flags.
+
+## Session ownership without data sharing
+
+The renderer binds each page to the actual terminal tab/workspace and current
+focused child session. It passes only `netcatty.surface: terminal-sidebar` as
+the view context. Internal ownership IDs are used for host state scoping, not
+returned to the page or treated as resource grants. A future selected-session
+data API must establish its own live endpoint authority and permissions.
+
+Changing terminal tabs or workspace focus closes the old native view before
+the new one can receive focus. Session removal, pane close, withdrawal of a
+visible contribution, disable/update/uninstall and runtime loss remove the
+affected page. Unknown saved routes are pruned without opening them; restoring
+a layout never grants the page or any session-data permission. State buckets
+are for the plugin's own UI data, not an isolation boundary against that same
+plugin's already-authorized own-state API. Ordinary KV does not become synced.
+
+PersistentSidePanelPortal moves a stable mount between the actual pane,
+magnification host and hidden parking host. There is no fallback native view
+over the entire terminal layer. Native geometry follows host DOM relocation,
+resize and scrolling; duplicate geometry updates are suppressed. Hidden/inert
+or parked mounts cannot reveal a native view.
+
+## Focus and security surfaces
+
+The existing sandbox ViewHost, immutable package/protocol checks, own-command
+and view-state boundaries are reused. Embedded pages start hidden. Host
+dialogs and overlapping portals hide them, and main-process App Lock closes
+them. Escape is host-owned and closes the plugin pane.
+
+Native WebContents focus is reported only to its actual owner's trusted
+renderer using a canonical instance-ID event. It updates the selected pane;
+it does not expose an Electron object to the plugin. Revealing multiple panes
+does not focus all of them: only the host-selected pane can request focus.
+The main process verifies actual owner, visibility, foreground and unlocked
+state before honoring that request. A plugin has no SDK method to invoke the
+host focus bridge. No session or page text is added to focus/audit logs.
+
+## Example and evidence
+
+`com.netcatty.session-scratchpad` 0.1.0 asks only for its own `views`. It saves,
+reopens and clears explicitly typed synthetic text. Package instructions and
+minimal native actions are in its README. Repository tests use real split
+tree, layout state, persistent portal, launcher and embedded-view components;
+host tests cover owner-bound focus, hidden/locked refusal and withdrawal.
+Feature and permission admission, limits, old APIs and previous Vault/command
+fixes are checked on the same stack. Independent review, exact-SHA CI and
+parent native QA remain separate acceptance gates recorded on the Draft PR.
+
+ThemePack, selected context/terminal drafts and SFTP handles remain subsequent
+bounded stages. Adding a sidebar page does not count as implementing them.

docs/plugin-platform/theme-packs.md

@@ -0,0 +1,135 @@
+# Host color theme packs
+
+Theme packs contribute validated light and dark host colors. They cannot inject
+CSS, access host DOM, change layout, load remote resources, replace security
+controls, or apply themselves. The feature is `appearance.theme-packs`.
+
+## Install and select
+
+Use normal Settings > Plugins to install and enable a package. In Appearance,
+choose a plugin theme for the current light or dark mode, then select Preview or
+Apply. Preview changes only the current window and writes no preference. Cancel,
+closing Appearance, changing mode, package withdrawal, or a newer committed
+revision ends that preview. Apply saves a host-owned, device-local choice and
+refreshes other application windows. Restore default clears the plugin choice
+for that mode and selects Snow or Midnight. Selecting a built-in swatch also
+clears that mode's plugin choice. Failures remain visible and are not reported as
+successful applications.
+
+The current view environment is globally broadcast. To keep temporary previews
+local, it publishes **committed** theme tokens only. Plugin pages follow an
+applied theme through their existing environment subscription; they do not
+receive another window's temporary preview. This does not add an owner-local
+view environment API.
+
+## Data-only package
+
+A pure theme uses `main: { "data": "theme" }`, contributes only `themes`, and
+omits permissions, activation events and companions. Its code runtime is never
+started, including by the runtime supervisor's startup or explicit-start path.
+Browser code plugins may also declare themes; choosing a theme does not start a
+runtime or grant their functional permissions. Only enabled packages appear.
+
+```json
+{
+  "features": { "required": ["appearance.theme-packs"] },
+  "main": { "data": "theme" },
+  "contributes": {
+    "themes": [{
+      "id": "com.example.colors.forest",
+      "label": "Forest",
+      "variant": "light",
+      "entry": "forest.json"
+    }]
+  }
+}
+```
+
+This fragment belongs in an otherwise complete manifest. Contribution IDs use
+the package namespace. Palette paths are package-relative JSON files, included
+and checked by the normal CLI/package store. Hosts lacking the required feature
+reject compatibility deterministically.
+
+```json
+{ "formatVersion": 1, "base": "light", "colors": { "accent": "#166534" } }
+```
+
+Colors merge onto a fixed accessible light/dark host base. Only opaque `#RRGGBB`
+values and canonical semantic keys are accepted. The 15 editable keys cover
+background/foreground, card and popover pairs, secondary and muted pairs, accent,
+destructive and its foreground, border and input. Primary, ring and the accent
+foregrounds are derived together, matching the existing theme conversion.
+Nineteen output fields are not nineteen independent controls.
+
+Each package has at most 32 themes; each palette is at most 64 KiB; the catalog
+and validated cache contain at most 256 entries. Schema and contrast checks run
+before catalog publication. Text pairs and state colors require at least 4.5:1;
+control borders and focus information require at least 3:1 against their
+surfaces. Invalid palettes produce bounded, content-free diagnostics and cannot
+be previewed or applied. Files are read from verified immutable package roots,
+with bounded reads and a no-follow final file open.
+
+## Ownership, recovery and security appearance
+
+The host stores selections separately from plugin KV, settings sidecars and
+cloud sync. A reference binds plugin ID, theme ID, exact version, archive digest
+and variant. Application uses a revision check plus an active-package check just
+before the atomic preference/audit transaction. An audit write failure rolls
+back the selection. Audit records contain revision/action metadata, not palette
+or user content.
+
+Disable, uninstall, update, missing entries and integrity failures withdraw the
+palette. A saved missing reference remains visible as unavailable while the
+same-mode safe host palette is used; a changed package is not automatically
+applied. Preview owner and committed revision checks prevent a late cancellation
+from replacing another preview or a newer application.
+
+Host dialogs, App Lock, grant/revoke, host details, keychain panels, host-key
+prompts and the credential picker use fixed host security variables while a
+plugin theme is active. The pack controls no font, icon, opacity, CSS selector,
+button text or ordering. System forced-colors/high-contrast preferences use a
+fixed host high-contrast fallback. Personal accent, fonts, terminal choices and
+accessibility preferences retain their authority. Existing personal custom CSS
+remains a user setting and is not exposed to plugins.
+
+This first layer changes host semantic colors. Static terminal palette linkage,
+custom high-contrast variants, fonts, density, icons and backgrounds remain
+separate bounded follow-ups; their fields are not silently accepted here.
+
+## Example and validation
+
+`examples/plugins/forest-theme-pack` is a four-file data package with light and
+dark Forest accents. It requests no permissions and contains no JavaScript.
+The starter, Vault Scratchpad and Session Scratchpad pages now subscribe to the
+existing seven public HSL tokens through `theme.js`, dispose on page hide, and
+use responsive host-colored controls. No new styling RPC is needed.
+
+Local evidence includes normal CLI validation/packing, schema/admission and
+no-runtime checks; host catalog/identity/size/contrast/CAS/migration/atomic-audit
+checks; picker preview/apply/cancel/reset and stale-owner/withdrawal/high-contrast
+checks; and view-template initial/live environment/disposal checks. Exact-SHA
+CI, independent review and parent native multi-window/security-surface acceptance
+remain separate delivery gates. Local production builds do not establish them.
+
+### First review / CI delta
+
+The first review found that muted text was validated only against its namesake
+muted surface, although host descriptions and statuses also use it on background,
+card and popover surfaces. The validator now checks generic and muted text on
+all neutral surfaces that reuse those tokens. The white-on-white counterexample
+is rejected both by the pure validator and the host catalog. Forest light/dark
+palettes remain valid.
+
+The first exact-head test run `40317690002` failed with 15187 passing tests,
+one failure and 50 skips. Its single failure was the unchanged TERM-SSHD
+concurrent failure-release test expecting a particular invocation to reach OPEN
+first. Both calls perform asynchronous local-file preparation. The test now
+requires exactly one explicit Permission denied result, one successful result
+with matching bytes, and no rejected concurrent handle; it retains concurrency
+without assuming filesystem completion order. No transfer implementation changed.
+The test file's original SHA256 was identical in e5bd294c, 733f44c and fdeeaf74:
+`8b200d9f6a05ac5cd91fe4e0a95ea36a770d22267a6a0162b4c9fc927beb52a7`.
+This is source identity and a source-based ordering diagnosis, not a claim that a
+baseline runtime failure was reproduced locally. The updated test needs the new
+exact-head CI result. That same first run passed the added Vite browser-import
+smoke, resolving the earlier local temp-directory limitation for that head.

docs/plugin-platform/vault-pages.md

@@ -0,0 +1,80 @@
+# Vault extension pages
+
+`views.vault-pages` adds the `vault-page` view location. A package must require
+the feature and declare the existing `views` permission. Hosts without the
+feature reject the package deterministically. Existing view locations and API
+versions keep their behavior; there is no public plugin router or new Vault
+read/write permission.
+
+## User workflow
+
+Visible, enabled contributions appear in Vault's **Extensions** group. The
+host generates a namespaced route from the declared view ID, orders by declared
+order and ID, localizes the label, and resolves the declared icon through the
+existing safe icon pipeline. Built-in navigation and security entry points
+remain host-owned. Collapsed navigation retains source-labelled accessible
+buttons.
+
+Selecting a page mounts its existing sandbox WebContentsView in the Vault main
+content area. It does not create a top tab, use an aside overlay, open a
+connection, or share host/session/Vault records. The trusted host context
+contains only `netcatty.surface: vault-page`. The manager's existing Open action
+can select the same page through an internal host event; this is not exposed
+as a generic SDK navigation capability.
+
+The `vault-scratchpad` browser example lets the user type synthetic text, save
+it in the plugin's own view state, return to Hosts, reopen, and clear it. It
+does not create a Vault Note or enable automatic cloud sync. The fixture asks
+for only `views`; granting it does not approve another plugin or data access.
+
+## Ownership and lifecycle
+
+The host owns the route and validates the selected contribution against the
+current visible catalog. Missing IDs, disable/uninstall/update, a false `when`,
+failed activation or a host close return to Hosts. Focus restoration checks
+the current section and active tab so an old fallback cannot steal focus after
+a newer selection. Catalog listing does not activate a plugin.
+
+The embedded host reuses PluginViewHost, its ephemeral session, CSP, no-Node
+preload, protocol validation, own-command checks, and bounded own view state.
+No DOM or Electron object enters the SDK. A window-route-and-slot scope separates
+this page's state from other view placements; actual BrowserWindow ownership is
+validated separately and does not rely on that state key. This initial embedded slice
+closes on navigation away even if `retainContextWhenHidden` is declared.
+
+Each opening reserves an instance ID owned by its actual BrowserWindow before
+asynchronous activation. Close can cancel that reservation before native
+construction. Owner closure, shutdown and renderer cleanup prevent a late open
+from attaching; late responses are also closed by the renderer lifecycle
+controller. Current plugin version/runtime and `when` are checked before
+attachment and on subsequent contribution changes. Existing owner checks apply
+to bounds, visibility, close and view-state IPC.
+
+Host reload/renderer exit and a view renderer crash close the associated native
+page. Plain Escape in a Vault page is handled by the host and returns to Hosts;
+it does not dispatch a plugin command or expose a general navigation API.
+
+Native child views sit above React portals. A Vault page starts hidden; the
+trusted renderer reveals it only after checking the mount and host dialogs,
+menus, popovers, overlay panels and lock surfaces. Overlapping host surfaces
+hide the page. App Lock additionally closes all hosted plugin views and
+cancels pending opens in the main process; showing a view while locked fails.
+
+The shared manifest bound remains 128 views per package. Only one Vault page is
+mounted per owner; listing and routing do not create a background view queue.
+View-state JSON size limits and existing runtime/permission quotas remain in
+force. No page text or state is added to audit logs by this adapter.
+
+## Validation status
+
+Source tests cover normal catalog selection, the actual embedded content slot,
+host-modal occlusion, synchronous tab-away cleanup, withdrawn and invalid
+routes, internal host selection, delayed open cancellation, feature/permission
+admission, host ownership, `when` withdrawal and App Lock. Production build,
+aggregate host tests and precise-SHA CI are reported on the accompanying Draft
+PR. Parent native acceptance must use the packed browser example through
+normal Settings and record its exact source SHA/package hash. Unit tests do
+not substitute for that native acceptance.
+
+Terminal sidebar pages and selected-session DTOs remain separate stages. This
+page location does not make those capabilities available.

domain/pluginPermissionDescriptions.cjs

@@ -13,6 +13,7 @@ const PERMISSION_DESCRIPTIONS = {
   views: [false, "Plugin panels", "Display plugin-owned panels inside the app.", "插件面板", "在应用中显示插件自己的面板。"],
   "clipboard.read": [true, "Read clipboard", "Read copied text, which may contain passwords or other sensitive data.", "读取剪贴板", "读取复制的文本，其中可能包含密码或其他敏感数据。"],
   "clipboard.write": [true, "Write clipboard", "Replace clipboard content that you may paste elsewhere.", "写入剪贴板", "替换剪贴板内容，可能影响你随后粘贴的数据。"],
+  "terminal.selection.read": [true, "Share terminal selection", "Read only text explicitly previewed and shared from the selected live terminal. It may contain secrets. Each action requires approval.", "分享终端选区", "仅读取用户从当前活跃终端明确预览并分享的文本，可能包含秘密；每次操作均需确认。"],
   "terminal.metadata": [true, "Terminal metadata", "Read terminal/session details that may identify hosts and activity.", "终端元数据", "读取终端和会话信息，可能暴露主机及操作活动。"],
   "terminal.output": [true, "Read terminal output", "Receive terminal output through supported providers; it may contain credentials or private data.", "读取终端输出", "通过支持的提供器接收终端输出，其中可能包含凭据或隐私信息。"],
   "terminal.input": [true, "Send terminal input", "Send input to a terminal; input may execute commands or change a remote host.", "发送终端输入", "向终端发送输入，可能执行命令或更改远程主机。"],

domain/pluginRuntimePolicy.cjs

@@ -3,6 +3,14 @@
 // Shared by host placement, release admission, and the installed-package UI.
 // A Node entrypoint does not change default placement, but is not admitted to
 // the normal browser-only product path.
+function isStaticThemePack(manifest) {
+  return manifest?.main?.data === "theme" && Object.keys(manifest.main).length === 1
+    && Array.isArray(manifest.contributes?.themes) && manifest.contributes.themes.length > 0
+    && Object.keys(manifest.contributes).every((key) => key === "themes")
+    && !Object.keys(manifest.permissions ?? {}).length && !manifest.activationEvents?.length
+    && !manifest.companionExecutables?.length
+    && manifest.features?.required?.includes("appearance.theme-packs");
+}
 function describePluginRuntime(manifest) {
   const providers = manifest?.contributes?.providers ?? [];
   const permissions = [...(manifest?.permissions?.required ?? []), ...(manifest?.permissions?.optional ?? [])];
@@ -18,19 +26,20 @@ function describePluginRuntime(manifest) {
   const hasNode = Boolean(manifest?.main?.node);
   const defaultRuntimeKind = hasBrowser && !hasCompanions && !hasInterceptors ? "browser" : "utility";
   return {
-    defaultRuntimeKind,
+    defaultRuntimeKind: isStaticThemePack(manifest) ? "data" : defaultRuntimeKind,
+    dataOnly: isStaticThemePack(manifest),
     hasNode,
     declaresAdvanced,
-    browserOnly: hasBrowser && !hasNode && !hasCompanions && !hasInterceptors && !declaresAdvanced,
+    browserOnly: !manifest?.main?.data && hasBrowser && !hasNode && !hasCompanions && !hasInterceptors && !declaresAdvanced,
   };
 }
 
 function assertBrowserOnlyPlugin(manifest) {
-  if (!describePluginRuntime(manifest).browserOnly) {
+  if (!describePluginRuntime(manifest).browserOnly && !isStaticThemePack(manifest)) {
     const error = new Error("This package requires advanced developer mode; normal plugin management accepts browser-only packages");
     error.code = "PLUGIN_UNSUPPORTED_RUNTIME";
     throw error;
   }
 }
 
-module.exports = { describePluginRuntime, assertBrowserOnlyPlugin };
+module.exports = { describePluginRuntime, assertBrowserOnlyPlugin, isStaticThemePack };

domain/pluginRuntimePolicy.test.cjs

@@ -19,3 +19,9 @@ test('normal release admission rejects advanced declarations and privileged prov
   assert.equal(describePluginRuntime(manifest).defaultRuntimeKind, 'utility');
   assert.throws(() => assertBrowserOnlyPlugin(manifest), /developer mode/);
 });
+
+test('normal admission accepts only explicit non-executable theme-only data packages',()=>{
+ const manifest={main:{data:'theme'},features:{required:['appearance.theme-packs']},contributes:{themes:[{id:'com.example.theme.light'}]}};
+ assert.doesNotThrow(()=>assertBrowserOnlyPlugin(manifest));assert.equal(describePluginRuntime(manifest).dataOnly,true);assert.equal(describePluginRuntime(manifest).defaultRuntimeKind,'data');
+ for(const change of [{main:{data:'theme',browser:'index.js'}},{permissions:{required:['network']}},{activationEvents:['onStartupFinished']},{contributes:{themes:[],commands:[]}}])assert.throws(()=>assertBrowserOnlyPlugin({...manifest,...change}),/developer mode/);
+});

domain/pluginThemePack.cjs

@@ -0,0 +1,145 @@
+"use strict";
+// Pure color projection. Package/wire schema validation belongs to the host.
+const LIGHT = Object.freeze({
+  background: "#ffffff",
+  foreground: "#161a1d",
+  card: "#ffffff",
+  cardForeground: "#161a1d",
+  popover: "#ffffff",
+  popoverForeground: "#161a1d",
+  secondary: "#e5e7eb",
+  secondaryForeground: "#161a1d",
+  muted: "#f0f2f4",
+  mutedForeground: "#374151",
+  accent: "#1d4ed8",
+  destructive: "#b91c1c",
+  destructiveForeground: "#ffffff",
+  border: "#6b7280",
+  input: "#6b7280",
+});
+const DARK = Object.freeze({
+  background: "#111827",
+  foreground: "#f9fafb",
+  card: "#1f2937",
+  cardForeground: "#f9fafb",
+  popover: "#1f2937",
+  popoverForeground: "#f9fafb",
+  secondary: "#374151",
+  secondaryForeground: "#ffffff",
+  muted: "#273244",
+  mutedForeground: "#e5e7eb",
+  accent: "#93c5fd",
+  destructive: "#fca5a5",
+  destructiveForeground: "#111827",
+  border: "#9ca3af",
+  input: "#9ca3af",
+});
+function rgb(hex) {
+  return [1, 3, 5].map(
+    (offset) => parseInt(hex.slice(offset, offset + 2), 16) / 255,
+  );
+}
+function luminance(hex) {
+  return rgb(hex)
+    .map((v) => (v <= 0.04045 ? v / 12.92 : ((v + 0.055) / 1.055) ** 2.4))
+    .reduce((s, v, i) => s + v * [0.2126, 0.7152, 0.0722][i], 0);
+}
+function contrast(a, b) {
+  const x = luminance(a),
+    y = luminance(b);
+  return (Math.max(x, y) + 0.05) / (Math.min(x, y) + 0.05);
+}
+function toHsl(hex) {
+  const [r, g, b] = rgb(hex),
+    max = Math.max(r, g, b),
+    min = Math.min(r, g, b),
+    delta = max - min,
+    l = (max + min) / 2;
+  let h = 0;
+  if (delta)
+    h =
+      (max === r
+        ? ((g - b) / delta + 6) % 6
+        : max === g
+          ? (b - r) / delta + 2
+          : (r - g) / delta + 4) * 60;
+  const s = delta ? delta / (1 - Math.abs(2 * l - 1)) : 0;
+  return `${h.toFixed(3)} ${(s * 100).toFixed(3)}% ${(l * 100).toFixed(3)}%`;
+}
+// A small margin covers rounding when hex colors become HSL CSS components.
+function resolveThemePalette(palette) {
+  const colors = {
+    ...(palette.base === "dark" ? DARK : LIGHT),
+    ...palette.colors,
+  };
+  for (const value of Object.values(colors))
+    if (!/^#[0-9a-f]{6}$/i.test(value)) throw new Error("Invalid theme color");
+  const pairs = [
+    ["foreground", "background"],
+    ["cardForeground", "card"],
+    ["popoverForeground", "popover"],
+    ["secondaryForeground", "secondary"],
+    ["mutedForeground", "muted"],
+    ["destructiveForeground", "destructive"],
+  ];
+  for (const [a, b] of pairs)
+    if (contrast(colors[a], colors[b]) < 4.51)
+      throw new Error("Theme text contrast is below 4.5:1");
+  // Host labels and descriptions reuse these text tokens across neutral
+  // surfaces; they do not always sit on their namesake background token.
+  for (const surface of ["background", "card", "popover", "secondary", "muted"])
+    for (const key of ["foreground", "mutedForeground"])
+      if (contrast(colors[key], colors[surface]) < 4.51)
+        throw new Error("Theme neutral-surface text contrast is below 4.5:1");
+  for (const surface of ["background", "card", "popover"]) {
+    for (const key of ["accent", "destructive"])
+      if (contrast(colors[key], colors[surface]) < 4.51)
+        throw new Error("Theme state contrast is below 4.5:1");
+    for (const key of ["border", "input"])
+      if (contrast(colors[key], colors[surface]) < 3.01)
+        throw new Error("Theme control contrast is below 3:1");
+  }
+  const foreground =
+    contrast(colors.accent, "#000000") >= contrast(colors.accent, "#ffffff")
+      ? "#000000"
+      : "#ffffff";
+  const tokens = Object.fromEntries(
+    Object.entries(colors).map(([k, v]) => [k, toHsl(v)]),
+  );
+  return Object.freeze({
+    ...tokens,
+    primary: tokens.accent,
+    primaryForeground: toHsl(foreground),
+    accentForeground: toHsl(foreground),
+    ring: tokens.accent,
+  });
+}
+function securityThemeTokens(mode, highContrast = false) {
+  const colors = highContrast
+    ? mode === "dark"
+      ? {
+          background: "#000000",
+          card: "#000000",
+          popover: "#000000",
+          foreground: "#ffffff",
+          cardForeground: "#ffffff",
+          popoverForeground: "#ffffff",
+          accent: "#ffff00",
+          border: "#ffffff",
+          input: "#ffffff",
+        }
+      : {
+          background: "#ffffff",
+          card: "#ffffff",
+          popover: "#ffffff",
+          foreground: "#000000",
+          cardForeground: "#000000",
+          popoverForeground: "#000000",
+          accent: "#000080",
+          border: "#000000",
+          input: "#000000",
+        }
+    : {};
+  return resolveThemePalette({ base: mode, colors });
+}
+module.exports = { resolveThemePalette, securityThemeTokens, contrast, toHsl };

domain/pluginThemePack.test.cjs

@@ -0,0 +1,33 @@
+const assert = require("node:assert/strict");
+const test = require("node:test");
+const {
+  resolveThemePalette,
+  securityThemeTokens,
+  contrast,
+} = require("./pluginThemePack.cjs");
+test("opaque accessible palettes derive coupled accent tokens and fixed high contrast fallback", () => {
+  for (const mode of ["light", "dark"]) {
+    const tokens = resolveThemePalette({ base: mode, colors: {} });
+    assert.equal(tokens.primary, tokens.accent);
+    assert.equal(tokens.ring, tokens.accent);
+    assert.equal(tokens.primaryForeground, tokens.accentForeground);
+    assert.ok(securityThemeTokens(mode, true));
+  }
+  assert.ok(contrast("#000000", "#ffffff") > 20);
+  assert.throws(
+    () =>
+      resolveThemePalette({ base: "light", colors: { foreground: "#ffffff" } }),
+    /contrast/,
+  );
+});
+
+test("generic and muted text stay readable on the neutral surfaces that use them", () => {
+  for (const colors of [
+    { muted: "#000000", mutedForeground: "#ffffff" },
+    { card: "#000000", cardForeground: "#ffffff" },
+    { popover: "#000000", popoverForeground: "#ffffff" },
+    { secondary: "#000000", secondaryForeground: "#ffffff" },
+  ]) {
+    assert.throws(() => resolveThemePalette({ base: "light", colors }), /contrast/);
+  }
+});

domain/sidePanelLayout.ts

@@ -1,4 +1,4 @@
-export type SidePanelTool =
+export type BuiltinSidePanelTool =
   | 'sftp'
   | 'browser'
   | 'scripts'
@@ -8,6 +8,12 @@ export type SidePanelTool =
   | 'system'
   | 'notes';
 
+export type SidePanelTool = BuiltinSidePanelTool | `plugin-view:${string}`;
+
+export function isPluginSidePanelTool(value: unknown): value is `plugin-view:${string}` {
+  return typeof value === 'string' && value.length <= 256 && /^plugin-view:[A-Za-z0-9_.-]+$/.test(value);
+}
+
 export type SidePanelSplitDirection = 'horizontal' | 'vertical';
 
 export type SidePanelPaneNode = {

domain/workspaceLayoutPreset.test.ts

@@ -90,6 +90,21 @@ test('sanitize accepts a valid saved preset and rejects malformed data', () => {
   );
 });
 
+test('plugin panes keep split uniqueness and limits; saved routes grant no availability and can be pruned', () => {
+  const tool = 'plugin-view:com.example.plugin.page' as const;
+  let layout = createSidePanelLayout('notes', 'notes');
+  layout = splitSidePanelPane(layout, 'notes', tool, 'vertical', { paneId: 'plugin', splitId: 'root' }, 600);
+  const unique = splitSidePanelPane(layout, 'notes', tool, 'vertical', { paneId: 'duplicate', splitId: 'unused' }, 600);
+  assert.equal(collectSidePanelPanes(unique.root).length, 2);
+  assert.equal(getFocusedSidePanelPane(unique).tool, tool);
+  assert.ok(createWorkspaceLayoutPreset(layout));
+  assert.equal(withoutUnavailableSidePanelTools(layout, (item) => item === 'notes')?.root.type, 'pane');
+  for (let i = 0; i < 10; i++) layout = splitSidePanelPane(layout, getFocusedSidePanelPane(layout).id,
+    `plugin-view:com.example.plugin.page${i}`, 'horizontal', { paneId: `p${i}`, splitId: `s${i}` }, 600);
+  assert.equal(collectSidePanelPanes(layout.root).length, 8);
+  assert.equal(sanitizeWorkspaceLayoutPreset({ version: 1, layout: { root: { id: 'invalid', type: 'pane', tool: 'plugin-view:../outside' }, focusedPaneId: 'invalid' } }), null);
+});
+
 test('sanitize rejects duplicate node ids', () => {
   assert.equal(
     sanitizeWorkspaceLayoutPreset({

domain/workspaceLayoutPreset.ts

@@ -3,6 +3,7 @@ import {
   closeSidePanelPane,
   collectSidePanelPanes,
   getFocusedSidePanelPane,
+  isPluginSidePanelTool,
   type SidePanelLayout,
   type SidePanelLayoutNode,
   type SidePanelTool,
@@ -32,7 +33,7 @@ const SIDE_PANEL_TOOLS: ReadonlySet<SidePanelTool> = new Set([
 ]);
 
 function isSidePanelTool(value: unknown): value is SidePanelTool {
-  return typeof value === 'string' && SIDE_PANEL_TOOLS.has(value as SidePanelTool);
+  return typeof value === 'string' && (SIDE_PANEL_TOOLS.has(value as SidePanelTool) || isPluginSidePanelTool(value));
 }
 
 function sanitizeSidePanelLayoutNode(

electron-builder.config.cjs

@@ -70,6 +70,7 @@ module.exports = {
         'domain/terminalPromptSecurity.shared.cjs',
         'domain/pluginRuntimePolicy.cjs',
         'domain/pluginPermissionDescriptions.cjs',
+        'domain/pluginThemePack.cjs',
         // Main-process SSH, SFTP, and port-forward bridges share this matcher.
         // TypeScript under domain/ is excluded below, so the .cjs must be listed.
         'domain/systemManager/containerRuntime.shared.cjs',

electron/bridges/terminalWorkerManager.cjs

@@ -390,6 +390,7 @@ function createTerminalWorkerManager(options = {}) {
     onRendererEvent = null,
   } = options;
   let child = null;
+  let pluginSessionAuthorityEpoch = 0;
   const pending = new Map();
   const pendingOutput = new Map();
   const pendingOutputBytes = new Map();
@@ -1857,6 +1858,7 @@ function createTerminalWorkerManager(options = {}) {
       },
     });
     child = worker;
+    pluginSessionAuthorityEpoch++;
     worker.on?.("message", (message) => {
       if (child === worker) handleMessage(message);
     });
@@ -2246,6 +2248,14 @@ function createTerminalWorkerManager(options = {}) {
       if (!sessionId) return null;
       return sessionWebContentsIds.get(sessionId) ?? null;
     },
+    // Main-process resource authority only; never expose worker objects or endpoints.
+    getPluginSessionBinding(sessionId, webContentsId) {
+      const generation = sessionGenerations.get(sessionId);
+      if (!child || !Number.isSafeInteger(generation) || closedSessions.has(sessionId)
+        || pendingSessionStartSequences.has(sessionId) || outputRoutePending.has(sessionId)
+        || sessionWebContentsIds.get(sessionId) !== webContentsId || !isLiveWebContentsId(webContentsId)) return null;
+      return Object.freeze({ epoch: pluginSessionAuthorityEpoch, generation });
+    },
     getSessionHostId(sessionId) {
       if (!sessionId) return null;
       return sessionHostIds.get(sessionId) ?? null;

electron/bridges/transferBridge.termSshd.test.cjs

@@ -311,7 +311,7 @@ test("TERM-SSHD queued cancellation releases its turn without closing the owner
   assert.equal(transferBridge._getSessionFastDownloadWaiterCountForTests(fixture.sftp), 0);
 });
 
-test("TERM-SSHD failed transfer releases the physical channel for the next alias", async (t) => {
+test("TERM-SSHD failed transfer releases the physical channel for the next alias", { timeout: 5_000 }, async (t) => {
   const fixture = await createSequentialTransferFixture(t);
   const originalOpen = fixture.sftp.open;
   let rejectFirst = true;
@@ -321,10 +321,16 @@ test("TERM-SSHD failed transfer releases the physical channel for the next alias
       args.at(-1)(Object.assign(new Error("Permission denied"), { code: 3 }));
     } else originalOpen(...args);
   };
-  const [first, next] = await Promise.all([fixture.start("download"), fixture.start("download", "alias")]);
-  assert.match(first.result.error || "", /Permission denied/);
-  assert.equal(next.result.error, undefined);
-  assert.deepEqual(await fs.readFile(next.targetPath), fixture.payload);
+  const transfers = await Promise.all([fixture.start("download"), fixture.start("download", "alias")]);
+  // Both calls await local file preparation before acquiring the shared channel.
+  // Either invocation may reach the injected first OPEN failure; retain the
+  // concurrent release check without assuming filesystem completion order.
+  const failed = transfers.filter((transfer) => transfer.result.error !== undefined);
+  const succeeded = transfers.filter((transfer) => transfer.result.error === undefined);
+  assert.equal(failed.length, 1);
+  assert.equal(succeeded.length, 1);
+  assert.match(failed[0].result.error, /Permission denied/);
+  assert.deepEqual(await fs.readFile(succeeded[0].targetPath), fixture.payload);
   assert.equal(fixture.rejectedOpens(), 0);
 });
 

electron/main/registerBridges.cjs

@@ -166,6 +166,7 @@ function createBridgeRegistrar(context) {
           electron: electronModule,
           safeStorage,
           getInteractionWindow: () => win,
+          getTerminalWorkerManager: () => terminalWorkerManager,
           isAppLocked: () => getAppLockController?.()?.getRuntimeState?.()?.locked !== false,
           subscribeAppLock: (listener) => getAppLockController?.()?.subscribe?.(listener),
           requestPermissionDecision: createNativePermissionDecisionProvider({
@@ -244,6 +245,7 @@ function createBridgeRegistrar(context) {
       },
       resolveBrandIcon: (pluginId) => pluginHostService?.contributionIconService?.resolveBrand(pluginId),
       resolveContributionIcon: (payload) => pluginHostService?.contributionIconService?.resolve(payload),
+      themeService: pluginHostService?.themeService,
       viewHost: pluginHostService?.viewHost,
       env: process.env,
       isTrustedSender: createTrustedPluginBridgeSender({ devServerUrl: effectiveDevServerUrl }),

electron/plugins/database.cjs

@@ -5,10 +5,11 @@ const fs = require("node:fs");
 const path = require("node:path");
 const { DatabaseSync } = require("node:sqlite");
 
-const SCHEMA_VERSION = 3;
+const SCHEMA_VERSION = 4;
 const MAX_SECURITY_AUDIT_DETAILS_BYTES = 16 * 1024;
 const MAX_SECURITY_AUDIT_RECORDS_PER_PLUGIN = 1_000;
 const REQUIRED_SCHEMA_COLUMNS = Object.freeze({
+  plugin_host_preferences: ["key", "value_json", "updated_at"],
   plugins: ["id", "enabled", "active_version", "installed_at", "updated_at"],
   plugin_versions: ["plugin_id", "version", "manifest_json", "archive_sha256", "package_relative_path", "installed_at"],
   plugin_runtime_state: ["plugin_id", "plugin_version", "status", "runtime_kind", "last_error", "quarantined_at", "updated_at"],
@@ -212,6 +213,10 @@ class PluginDatabase {
         `);
       });
     }
+    if (version <= 3) this.transaction(() => this.db.exec(`
+      CREATE TABLE plugin_host_preferences (key TEXT PRIMARY KEY, value_json TEXT NOT NULL, updated_at INTEGER NOT NULL);
+      PRAGMA user_version = 4;
+    `));
     this.#assertSchemaLayout();
     // Legacy-map backfill is deferred until PackageStore.recover() has finished
     // (hostService seeds after package initialize). Running here would promote
@@ -1030,18 +1035,34 @@ class PluginDatabase {
         sha256: createHash("sha256").update(detailsJson).digest("hex"),
       });
     }
+    this.transaction(() => this.#appendSecurityAudit(pluginId, event, detailsJson));
+  }
+
+  #appendSecurityAudit(pluginId, event, detailsJson) {
+    this.db.prepare(`
+      INSERT INTO plugin_security_audit(plugin_id, event, details_json, created_at)
+      VALUES (?, ?, ?, ?)
+    `).run(pluginId, event, detailsJson, this.clock());
+    this.db.prepare(`
+      DELETE FROM plugin_security_audit
+      WHERE plugin_id = ? AND id NOT IN (
+        SELECT id FROM plugin_security_audit
+        WHERE plugin_id = ? ORDER BY id DESC LIMIT ${MAX_SECURITY_AUDIT_RECORDS_PER_PLUGIN}
+      )
+    `).run(pluginId, pluginId);
+  }
+
+  getHostThemeSelection() {
+    const row = this.db.prepare("SELECT value_json FROM plugin_host_preferences WHERE key = 'theme'").get();
+    return row ? parseJson(row.value_json, "host theme selection") : {formatVersion: 1, revision: 0, light: null, dark: null};
+  }
+
+  commitHostThemeSelection(expectedRevision, selection, pluginId) {
     this.transaction(() => {
-      this.db.prepare(`
-        INSERT INTO plugin_security_audit(plugin_id, event, details_json, created_at)
-        VALUES (?, ?, ?, ?)
-      `).run(pluginId, event, detailsJson, this.clock());
-      this.db.prepare(`
-        DELETE FROM plugin_security_audit
-        WHERE plugin_id = ? AND id NOT IN (
-          SELECT id FROM plugin_security_audit
-          WHERE plugin_id = ? ORDER BY id DESC LIMIT ${MAX_SECURITY_AUDIT_RECORDS_PER_PLUGIN}
-        )
-      `).run(pluginId, pluginId);
+      if (this.getHostThemeSelection().revision !== expectedRevision) throw new Error("Theme selection changed; refresh before applying");
+      this.db.prepare("INSERT INTO plugin_host_preferences(key,value_json,updated_at) VALUES('theme',?,?) ON CONFLICT(key) DO UPDATE SET value_json=excluded.value_json,updated_at=excluded.updated_at")
+        .run(JSON.stringify(selection), this.clock());
+      this.#appendSecurityAudit(pluginId ?? "$host.appearance", "theme-selection", JSON.stringify({revision:selection.revision, action:pluginId ? "apply" : "restore"}));
     });
   }
 

electron/plugins/generated/plugin-contract.schema.json

@@ -390,6 +390,9 @@
         },
         {
           "$ref": "#/$defs/HostClipboardWriteRequest"
+        },
+        {
+          "$ref": "#/$defs/HostTerminalSelectionReadRequest"
         }
       ]
     },
@@ -426,6 +429,9 @@
                 },
                 {
                   "const": true
+                },
+                {
+                  "$ref": "#/$defs/SharedTerminalSelection"
                 }
               ]
             }
@@ -536,6 +542,11 @@
           "type": "string",
           "maxLength": 4096,
           "pattern": "^[^\\u0000]*$"
+        },
+        "terminalSessionId": {
+          "type": "string",
+          "maxLength": 128,
+          "pattern": "^[A-Za-z0-9_-]+$"
         }
       },
       "additionalProperties": false
@@ -731,7 +742,8 @@
         "provider.connection",
         "provider.authentication",
         "provider.sync",
-        "provider.importer"
+        "provider.importer",
+        "terminal.selection.read"
       ]
     },
     "NonResourceScopedPermission": {
@@ -765,7 +777,8 @@
         "provider.connection",
         "provider.authentication",
         "provider.sync",
-        "provider.importer"
+        "provider.importer",
+        "terminal.selection.read"
       ]
     },
     "ResourceScopedPermission": {
@@ -872,7 +885,10 @@
         {
           "$ref": "#/$defs/RequiredPermissionResourceDeclaration"
         }
-      ]
+      ],
+      "not": {
+        "const": "terminal.selection.read"
+      }
     },
     "PermissionSet": {
       "type": "object",
@@ -902,10 +918,27 @@
         },
         "node": {
           "$ref": "#/$defs/RelativePackagePath"
+        },
+        "data": {
+          "const": "theme"
         }
       },
       "minProperties": 1,
-      "additionalProperties": false
+      "additionalProperties": false,
+      "if": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "const": "theme"
+          }
+        }
+      },
+      "then": {
+        "maxProperties": 1
+      }
     },
     "PluginEngines": {
       "type": "object",
@@ -1293,9 +1326,34 @@
         "panel",
         "tab",
         "modal",
-        "settings"
+        "settings",
+        "vault-page",
+        "terminal-sidebar"
       ]
     },
+    "VaultPagesFeature": {
+      "const": "views.vault-pages"
+    },
+    "TerminalSidebarFeature": {
+      "const": "views.terminal-sidebar"
+    },
+    "PluginViewFocusEvent": {
+      "type": "object",
+      "required": [
+        "instanceId"
+      ],
+      "properties": {
+        "instanceId": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128
+        }
+      },
+      "additionalProperties": false
+    },
+    "PluginViewFocusRequest": {
+      "$ref": "#/$defs/PluginViewFocusEvent"
+    },
     "ViewContribution": {
       "type": "object",
       "required": [
@@ -3270,6 +3328,14 @@
     "PluginContributions": {
       "type": "object",
       "properties": {
+        "themes": {
+          "type": "array",
+          "maxItems": 32,
+          "items": {
+            "$ref": "#/$defs/ThemePackContribution"
+          },
+          "minItems": 1
+        },
         "settings": {
           "type": "array",
           "maxItems": 512,
@@ -3432,7 +3498,51 @@
           }
         }
       },
-      "additionalProperties": false
+      "additionalProperties": false,
+      "if": {
+        "properties": {
+          "main": {
+            "required": [
+              "data"
+            ],
+            "type": "object",
+            "properties": {
+              "data": {
+                "const": "theme"
+              }
+            }
+          }
+        }
+      },
+      "then": {
+        "properties": {
+          "contributes": {
+            "required": [
+              "themes"
+            ],
+            "maxProperties": 1,
+            "type": "object",
+            "properties": {
+              "themes": true
+            }
+          },
+          "permissions": {
+            "maxProperties": 0,
+            "type": "object"
+          },
+          "activationEvents": {
+            "maxItems": 0,
+            "type": "array"
+          },
+          "companionExecutables": {
+            "maxItems": 0,
+            "type": "array"
+          }
+        },
+        "required": [
+          "contributes"
+        ]
+      }
     },
     "RpcId": {
       "oneOf": [
@@ -4747,6 +4857,399 @@
           "additionalProperties": false
         }
       ]
+    },
+    "ThemePackFeature": {
+      "const": "appearance.theme-packs"
+    },
+    "ThemePackLimits": {
+      "const": {
+        "jsonBytes": 65536,
+        "catalogEntries": 256,
+        "themesPerPackage": 32
+      }
+    },
+    "ThemePackVariant": {
+      "type": "string",
+      "enum": [
+        "light",
+        "dark"
+      ]
+    },
+    "ThemePackContribution": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "$ref": "#/$defs/ContributionId"
+        },
+        "label": {
+          "$ref": "#/$defs/LocalizedText"
+        },
+        "variant": {
+          "$ref": "#/$defs/ThemePackVariant"
+        },
+        "entry": {
+          "$ref": "#/$defs/RelativePackagePath"
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "id",
+        "label",
+        "variant",
+        "entry"
+      ]
+    },
+    "ThemePackColors": {
+      "type": "object",
+      "properties": {
+        "background": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "foreground": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "card": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "cardForeground": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "popover": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "popoverForeground": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "secondary": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "secondaryForeground": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "muted": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "mutedForeground": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "accent": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "destructive": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "destructiveForeground": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "border": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        },
+        "input": {
+          "type": "string",
+          "pattern": "^#[0-9A-Fa-f]{6}$"
+        }
+      },
+      "additionalProperties": false,
+      "minProperties": 1
+    },
+    "ThemePackPalette": {
+      "type": "object",
+      "properties": {
+        "formatVersion": {
+          "const": 1
+        },
+        "base": {
+          "type": "string",
+          "enum": [
+            "light",
+            "dark"
+          ]
+        },
+        "colors": {
+          "$ref": "#/$defs/ThemePackColors"
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "formatVersion",
+        "base",
+        "colors"
+      ]
+    },
+    "ThemePackReference": {
+      "type": "object",
+      "properties": {
+        "pluginId": {
+          "$ref": "#/$defs/PluginId"
+        },
+        "themeId": {
+          "$ref": "#/$defs/ContributionId"
+        },
+        "version": {
+          "$ref": "#/$defs/SemanticVersion"
+        },
+        "digest": {
+          "type": "string",
+          "pattern": "^[a-f0-9]{64}$"
+        },
+        "variant": {
+          "$ref": "#/$defs/ThemePackVariant"
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "pluginId",
+        "themeId",
+        "version",
+        "digest",
+        "variant"
+      ]
+    },
+    "ThemePackChoice": {
+      "type": "object",
+      "properties": {
+        "ref": {
+          "$ref": "#/$defs/ThemePackReference"
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "ref"
+      ]
+    },
+    "ThemePackSelection": {
+      "type": "object",
+      "properties": {
+        "formatVersion": {
+          "const": 1
+        },
+        "revision": {
+          "$ref": "#/$defs/SafeUnsignedInteger"
+        },
+        "light": {
+          "oneOf": [
+            {
+              "$ref": "#/$defs/ThemePackChoice"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "dark": {
+          "oneOf": [
+            {
+              "$ref": "#/$defs/ThemePackChoice"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "formatVersion",
+        "revision",
+        "light",
+        "dark"
+      ]
+    },
+    "ThemePackApplyRequest": {
+      "type": "object",
+      "properties": {
+        "expectedRevision": {
+          "$ref": "#/$defs/SafeUnsignedInteger"
+        },
+        "mode": {
+          "type": "string",
+          "enum": [
+            "light",
+            "dark"
+          ]
+        },
+        "choice": {
+          "oneOf": [
+            {
+              "$ref": "#/$defs/ThemePackChoice"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "expectedRevision",
+        "mode",
+        "choice"
+      ]
+    },
+    "ThemePackEntry": {
+      "type": "object",
+      "properties": {
+        "ref": {
+          "$ref": "#/$defs/ThemePackReference"
+        },
+        "label": {
+          "type": "string",
+          "maxLength": 512
+        },
+        "pluginName": {
+          "type": "string",
+          "maxLength": 512
+        },
+        "dataOnly": {
+          "type": "boolean"
+        },
+        "palette": {
+          "$ref": "#/$defs/ThemePackPalette"
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "ref",
+        "label",
+        "pluginName",
+        "dataOnly",
+        "palette"
+      ]
+    },
+    "ThemePackCatalog": {
+      "type": "object",
+      "properties": {
+        "selection": {
+          "$ref": "#/$defs/ThemePackSelection"
+        },
+        "entries": {
+          "type": "array",
+          "maxItems": 256,
+          "items": {
+            "$ref": "#/$defs/ThemePackEntry"
+          }
+        },
+        "diagnostics": {
+          "type": "array",
+          "maxItems": 256,
+          "items": {
+            "type": "object",
+            "properties": {
+              "pluginId": {
+                "$ref": "#/$defs/PluginId"
+              },
+              "themeId": {
+                "type": "string",
+                "maxLength": 192
+              },
+              "code": {
+                "type": "string",
+                "enum": [
+                  "invalid",
+                  "unavailable",
+                  "capacity"
+                ]
+              }
+            },
+            "additionalProperties": false,
+            "required": [
+              "pluginId",
+              "code"
+            ]
+          }
+        }
+      },
+      "additionalProperties": false,
+      "required": [
+        "selection",
+        "entries",
+        "diagnostics"
+      ]
+    },
+    "TerminalSelectionSharingFeature": {
+      "const": "terminal.selection-sharing"
+    },
+    "TerminalSelectionSharingLimits": {
+      "const": {
+        "textBytes": 4096,
+        "handleTtlMs": 120000,
+        "handlesPerRuntime": 4,
+        "handlesTotal": 64
+      }
+    },
+    "HostTerminalTarget": {
+      "type": "object",
+      "properties": {
+        "sessionId": {
+          "type": [
+            "string",
+            "null"
+          ],
+          "maxLength": 128,
+          "pattern": "^[A-Za-z0-9_-]+$"
+        }
+      },
+      "required": [
+        "sessionId"
+      ],
+      "additionalProperties": false
+    },
+    "HostTerminalSelectionReadRequest": {
+      "type": "object",
+      "properties": {
+        "kind": {
+          "const": "terminal.selection.read"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 256
+        }
+      },
+      "required": [
+        "kind",
+        "title"
+      ],
+      "additionalProperties": false
+    },
+    "SharedTerminalSelection": {
+      "type": "object",
+      "properties": {
+        "text": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 4096,
+          "pattern": "^[^\\u0000]*$"
+        },
+        "handle": {
+          "type": "string",
+          "minLength": 64,
+          "maxLength": 256
+        },
+        "expiresAt": {
+          "$ref": "#/$defs/SafePositiveInteger"
+        }
+      },
+      "required": [
+        "text",
+        "handle",
+        "expiresAt"
+      ],
+      "additionalProperties": false
     }
   }
 }

electron/plugins/hostInteractionService.cjs

@@ -2,6 +2,7 @@
 
 const { createHmac, randomBytes, randomUUID, timingSafeEqual } = require("node:crypto");
 const { createDefinitionValidator } = require("./contractValidator.cjs");
+const { TerminalSelectionAuthority } = require("./terminalSelectionAuthority.cjs");
 const { PluginRpcError, RPC_ERRORS } = require("./rpcRouter.cjs");
 const schema = require("./generated/plugin-contract.schema.json");
 const LIMITS = schema.$defs.HostInteractionLimits.const;
@@ -31,7 +32,12 @@ function assertInteractionRequest(params) {
   }
   return Object.freeze(structuredClone(params));
 }
-function interactionAuthorization(params) {
+function interactionAuthorization(params, terminalTarget) {
+  if (params.kind === "terminal.selection.read") {
+    if (!terminalTarget) throw fail("failedPrecondition", "A host-selected terminal is required");
+    return { permission: "terminal.selection.read", resources: [terminalTarget.resource],
+      reason: "Preview and explicitly share the selected terminal text", operationId: "terminal:share-selection", allowedScopes: ["once"] };
+  }
   const permission = params.kind === "clipboard.read" ? "clipboard.read"
     : params.kind === "clipboard.write" ? "clipboard.write" : "ui.interact";
   return {
@@ -55,6 +61,12 @@ class PluginHostInteractionService {
     this.timeoutMs = Math.min(options.timeoutMs ?? LIMITS.timeoutMs, LIMITS.timeoutMs);
     this.key = randomBytes(32);
     this.pending = new Map();
+    this.terminalSelection = new TerminalSelectionAuthority({getWindow: this.getWindow, getManager: options.getTerminalWorkerManager, clock: this.clock});
+    this.terminalInvalidation = this.terminalSelection.onDidInvalidate(() => {
+      for (const entry of [...this.pending.values()]) if (entry.terminalTarget && !this.terminalSelection.isCurrent(entry.terminalTarget)) {
+        this.#finish(entry, null, fail("cancelled", "Selected terminal connection changed"));
+      }
+    });
     this.rates = new Map();
     this.admissions = new WeakMap();
     this.admissionGuards = new Map();
@@ -75,8 +87,9 @@ class PluginHostInteractionService {
         const sender = this.#admit(params, context);
         let guard = this.admissionGuards.get(context.runtimeId);
         if (!guard) { guard = { active: true }; this.admissionGuards.set(context.runtimeId, guard); }
-        this.admissions.set(params, { sender, runtimeId: context.runtimeId, revision: this.admissionRevision, guard });
-        return interactionAuthorization(params);
+        const terminalTarget = params.kind === "terminal.selection.read" ? this.terminalSelection.capture(sender, context) : undefined;
+        this.admissions.set(params, { sender, runtimeId: context.runtimeId, revision: this.admissionRevision, guard, terminalTarget });
+        return interactionAuthorization(params, terminalTarget);
       },
     });
   }
@@ -132,7 +145,7 @@ class PluginHostInteractionService {
     const nonce = randomBytes(24).toString("base64url");
     const binding = JSON.stringify([
       nonce, entry.id, entry.context.pluginId, entry.context.pluginVersion,
-      entry.context.runtimeId, entry.sender.id, entry.params.kind, entry.phase, entry.expiresAt,
+      entry.context.runtimeId, entry.sender.id, entry.params.kind, entry.phase, entry.expiresAt, entry.terminalTarget?.resource ?? null,
     ]);
     return `${nonce}.${createHmac("sha256", this.key).update(binding).digest("base64url")}`;
   }
@@ -143,6 +156,7 @@ class PluginHostInteractionService {
       requestId: entry.id, actionToken: entry.actionToken,
       pluginId: entry.context.pluginId, pluginVersion: entry.context.pluginVersion,
       expiresAt: entry.expiresAt, phase: entry.phase, request: entry.params,
+      ...(entry.terminalTarget ? { terminalSessionId: entry.terminalTarget.sessionId } : {}),
       ...(entry.previewText === undefined ? {} : { previewText: entry.previewText }),
     });
   }
@@ -222,10 +236,13 @@ class PluginHostInteractionService {
     if (this.pending.size >= LIMITS.pendingTotal || [...this.pending.values()].some((entry) => entry.context.runtimeId === context.runtimeId || entry.sender === sender)) {
       throw fail("resourceExhausted", "Host interaction limit reached");
     }
+    const terminalTarget = params.kind === "terminal.selection.read"
+      ? admission?.terminalTarget ?? this.terminalSelection.capture(sender, context) : undefined;
+    if (terminalTarget) this.terminalSelection.assertCurrent(terminalTarget);
     const now = this.clock();
     return new Promise((resolve, reject) => {
       const entry = {
-        id: randomUUID(), context, params, sender, resolve, reject,
+        id: randomUUID(), context, params, sender, resolve, reject, terminalTarget,
         expiresAt: now + this.timeoutMs, phase: "request", actionToken: null,
       };
       entry.onAbort = () => this.#finish(entry, null, fail("cancelled", "Host interaction was cancelled"));
@@ -254,10 +271,19 @@ class PluginHostInteractionService {
       await entry.context.assertActive();
       this.#assertWindow(sender);
       if (this.pending.get(entry.id) !== entry) return false;
+      if (entry.terminalTarget) this.terminalSelection.assertCurrent(entry.terminalTarget);
       if (response.action === "cancel") {
         this.#audit(entry, "cancelled");
         return this.#finish(entry, { cancelled: true });
       }
+      if (entry.params.kind === "terminal.selection.read" && entry.phase === "request") {
+        if (response.action !== "preview") throw fail("invalidArgument", "Terminal sharing requires a preview action");
+        const text = assertTextBytes(response.value);
+        if (!text.length) throw fail("failedPrecondition", "Select terminal text before requesting a share");
+        this.#audit(entry, "preview-confirmed");
+        this.quotaManager.chargeBytes(entry.context.runtimeId, "terminal", Buffer.byteLength(text));
+        entry.previewText = text; entry.phase = "preview"; this.#present(entry); return true;
+      }
       if (entry.params.kind === "clipboard.read" && entry.phase === "request") {
         if (response.action !== "preview") throw fail("invalidArgument", "Clipboard sharing requires a preview action");
         this.#audit(entry, "preview-confirmed");
@@ -281,6 +307,9 @@ class PluginHostInteractionService {
       else if (entry.params.kind === "quickPick") {
         if (!entry.params.items.some((item) => item.id === response.value)) throw fail("invalidArgument", "Host interaction choice is invalid");
         value = response.value;
+      } else if (entry.params.kind === "terminal.selection.read") {
+        if (entry.phase !== "preview" || typeof entry.previewText !== "string") throw fail("failedPrecondition", "Terminal selection was not previewed");
+        value = {text:entry.previewText, ...this.terminalSelection.issue(entry.terminalTarget, entry.context)};
       } else if (entry.params.kind === "clipboard.read") value = entry.previewText;
       else value = true;
       this.#audit(entry, entry.params.kind === "clipboard.write" ? "copy-confirmed" : "share-confirmed");
@@ -295,8 +324,11 @@ class PluginHostInteractionService {
     }
   }
 
+  setTerminalTarget(sender, target) { return this.terminalSelection.setTarget(sender, target); }
+
   releaseWindow(sender) {
     if (this.owner !== sender) return;
+    this.terminalSelection.releaseWindow(sender);
     this.admissionRevision++;
     this.owner = null;
     this.ownerCleanup?.(); this.ownerCleanup = null;
@@ -305,12 +337,14 @@ class PluginHostInteractionService {
     }
   }
   releasePlugin(pluginId) {
+    this.terminalSelection.releasePlugin(pluginId);
     this.admissionRevision++;
     for (const entry of [...this.pending.values()]) {
       if (entry.context.pluginId === pluginId) this.#finish(entry, null, fail("cancelled", "Plugin access was revoked"));
     }
   }
   releaseRuntime(runtimeId) {
+    this.terminalSelection.releaseRuntime(runtimeId);
     this.cancelRuntimeRequests(runtimeId, "Plugin runtime stopped");
     this.rates.delete(runtimeId);
   }
@@ -323,7 +357,7 @@ class PluginHostInteractionService {
     }
   }
   cancelAll(invalidateAdmission = true) {
-    if (invalidateAdmission) this.admissionRevision++;
+    if (invalidateAdmission) { this.admissionRevision++; this.terminalSelection.clearHandles(); }
     for (const entry of [...this.pending.values()]) this.#finish(entry, null, fail("cancelled", "Host interaction was cancelled"));
   }
   shutdown() {
@@ -332,6 +366,7 @@ class PluginHostInteractionService {
     if (this.owner) this.releaseWindow(this.owner);
     this.cancelAll(); this.rates.clear(); this.admissionGuards.clear();
     this.revocation.dispose(); this.unsubscribeLock?.();
+    this.terminalInvalidation.dispose(); this.terminalSelection.shutdown();
     this.key.fill(0);
   }
 }

electron/plugins/hostService.cjs

@@ -2,6 +2,8 @@
 
 const path = require("node:path");
 const NETWORK_CREDENTIAL_LEASE_FEATURE = require("./generated/plugin-contract.schema.json").$defs.NetworkCredentialLeaseFeature.const;
+const VAULT_PAGES_FEATURE = require("./generated/plugin-contract.schema.json").$defs.VaultPagesFeature.const;
+const TERMINAL_SIDEBAR_FEATURE = require("./generated/plugin-contract.schema.json").$defs.TerminalSidebarFeature.const;
 const INTERACTIVE_COMMAND_FEATURE = require("./generated/plugin-contract.schema.json").$defs.InteractiveCommandFeature.const;
 
 const { assertBrowserOnlyPlugin } = require("../../domain/pluginRuntimePolicy.cjs");
@@ -20,6 +22,7 @@ const {
   normalizePluginModuleResources,
 } = require("./moduleResources.cjs");
 const { RegistryCatalogService } = require("./registryCatalogService.cjs");
+const { PluginThemeService } = require("./themeService.cjs");
 const { PackageStore } = require("./packageStore.cjs");
 const { createPluginPaths } = require("./paths.cjs");
 const { PluginManager } = require("./pluginManager.cjs");
@@ -96,7 +99,7 @@ function createPluginHostService(options) {
       database,
       netcattyVersion: options.app.getVersion(),
       apiVersion: PLUGIN_API_VERSION,
-      supportedFeatures: [...new Set(["metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, HOST_INTERACTION_FEATURE, INTERACTIVE_COMMAND_FEATURE, ...(options.supportedFeatures ?? [])])],
+      supportedFeatures: [...new Set(["terminal.selection-sharing", "appearance.theme-packs", "metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, HOST_INTERACTION_FEATURE, VAULT_PAGES_FEATURE, TERMINAL_SIDEBAR_FEATURE, INTERACTIVE_COMMAND_FEATURE, ...(options.supportedFeatures ?? [])])],
     });
     const contributionIconService = new PluginContributionIconService({
       database,
@@ -187,6 +190,7 @@ function createPluginHostService(options) {
       getWindow: options.getInteractionWindow,
       isLocked: options.isAppLocked,
       subscribeLock: options.subscribeAppLock,
+      getTerminalWorkerManager: options.getTerminalWorkerManager,
     });
     interactionService.registerRpcCapabilities(rpcRegistry);
     const configuredRegistry = options.configureRpcRegistry?.(rpcRegistry);
@@ -236,7 +240,7 @@ function createPluginHostService(options) {
       paths,
       netcattyVersion: options.app.getVersion(),
       apiVersion: PLUGIN_API_VERSION,
-      supportedFeatures: [...new Set(["metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, HOST_INTERACTION_FEATURE, INTERACTIVE_COMMAND_FEATURE, ...(options.supportedFeatures ?? [])])],
+      supportedFeatures: [...new Set(["terminal.selection-sharing", "appearance.theme-packs", "metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, HOST_INTERACTION_FEATURE, VAULT_PAGES_FEATURE, TERMINAL_SIDEBAR_FEATURE, INTERACTIVE_COMMAND_FEATURE, ...(options.supportedFeatures ?? [])])],
       runtimeDirectory,
       appRoot,
       rpcRegistry,
@@ -364,8 +368,11 @@ function createPluginHostService(options) {
           packageStore,
           database,
           contributionService,
+          isLocked: options.isAppLocked,
+          subscribeLock: options.subscribeAppLock,
         })
       : null;
+    const themeService = new PluginThemeService({database,packageStore,contributionService});
     const manager = new PluginManager({
       permissionEngine,
       database,
@@ -373,6 +380,7 @@ function createPluginHostService(options) {
       runtimeSupervisor,
       contributionService,
       beforeClose: async () => {
+        themeService.shutdown();
         interactionService.shutdown();
         terminalDataPipelineService?.shutdown();
         extensionProviderService.shutdown();
@@ -385,6 +393,7 @@ function createPluginHostService(options) {
       },
     });
     return {
+      themeService,
       interactionService,
       catalogService: new RegistryCatalogService({ manager, fetch: options.electron.net?.fetch?.bind(options.electron.net) }),
       companionSupervisor,

electron/plugins/packaging.test.cjs

@@ -23,6 +23,7 @@ test("packaged application declares every plugin host runtime dependency and res
   assert.match(builderSource, /electron\/plugins\/runtime\/\*\*\/\*/);
   assert.match(builderSource, /domain\/pluginRuntimePolicy\.cjs/);
   assert.match(builderSource, /domain\/pluginPermissionDescriptions\.cjs/);
+  assert.match(builderSource, /domain\/pluginThemePack\.cjs/);
   assert.match(builderSource, /!electron\/plugins\/fixtures\/\*\*\/\*/);
 });
 

electron/plugins/pluginBridge.cjs

@@ -5,6 +5,7 @@ const { randomUUID } = require("node:crypto");
 
 const { createDefinitionValidator } = require("./contractValidator.cjs");
 const validateManagedPluginId = createDefinitionValidator("PluginId");
+const validateViewFocus = createDefinitionValidator("PluginViewFocusRequest");
 
 const { raceWithAbort } = require("./rpcRouter.cjs");
 const {
@@ -15,7 +16,11 @@ const {
 const { assertSecretKey } = require("./secretStore.cjs");
 
 const CHANNELS = Object.freeze({
+  themeCatalog: "netcatty:plugins:theme-catalog",
+  themeApply: "netcatty:plugins:theme-apply",
+  themesChanged: "netcatty:plugins:themes-changed",
   status: "netcatty:plugins:status",
+  terminalTarget: "netcatty:plugins:terminal-target",
   interactionReady: "netcatty:plugins:interaction-ready",
   interactionResponse: "netcatty:plugins:interaction-response",
   list: "netcatty:plugins:list",
@@ -75,6 +80,7 @@ const CHANNELS = Object.freeze({
   importerProgress: "netcatty:plugins:importer-progress",
   openView: "netcatty:plugins:open-view",
   closeView: "netcatty:plugins:close-view",
+  focusView: "netcatty:plugins:focus-view",
   setViewBounds: "netcatty:plugins:set-view-bounds",
   setViewVisibility: "netcatty:plugins:set-view-visibility",
   viewMessage: "netcatty:plugins:view-message",
@@ -721,6 +727,19 @@ function registerPluginBridge(ipcMain, options) {
   ));
   handle(CHANNELS.restart, async (activeManager, payload) => activeManager.restart(payload?.pluginId));
   handle(CHANNELS.uninstall, async (activeManager, payload) => activeManager.uninstall(payload?.pluginId));
+  handle(CHANNELS.terminalTarget, async (_manager, target, event) => {
+    if (!options.interactionService) throw new Error("Host interactions unavailable");
+    return options.interactionService.setTerminalTarget(event.sender, target);
+  });
+  handle(CHANNELS.themeCatalog, async () => {
+    if (!options.themeService) throw new Error("Plugin themes are unavailable");
+    return options.themeService.catalog();
+  });
+  handle(CHANNELS.themeApply, async (_manager, request) => {
+    if (!options.themeService) throw new Error("Plugin themes are unavailable");
+    return options.themeService.apply(request);
+  });
+  options.themeService?.onDidChange?.(() => options.broadcast?.(CHANNELS.themesChanged, {}));
   handle(CHANNELS.contributions, async (_activeManager, payload) => {
     if (!contributionService) throw new Error("Plugin contributions are unavailable");
     return contributionService.snapshot(payload ?? {});
@@ -1605,6 +1624,12 @@ function registerPluginBridge(ipcMain, options) {
     await viewHost.close(payload?.instanceId, event.sender);
     return null;
   });
+  handle(CHANNELS.focusView, async (_activeManager, payload, event) => {
+    if (!viewHost) throw new Error("Plugin views are unavailable");
+    if (!validateViewFocus(payload)) throw new TypeError("Plugin view focus request is invalid");
+    viewHost.focus(payload.instanceId, event.sender);
+    return null;
+  });
   handle(CHANNELS.setViewBounds, async (_activeManager, payload, event) => {
     if (!viewHost) throw new Error("Plugin views are unavailable");
     viewHost.setBounds(payload?.instanceId, payload?.bounds, event.sender);

electron/plugins/pluginBridge.test.cjs

@@ -1714,3 +1714,10 @@ test("host interaction ready and response channels reject untrusted senders befo
   await ipcMain.handlers.get(CHANNELS.interactionResponse)({ trusted: true, sender }, response);
   assert.deepEqual(calls, [[sender, true], [sender, response]]);
 });
+
+test('theme catalog and selection remain trusted app management channels',async()=>{
+ const ipc=createIpcMain();let calls=0;
+ registerPluginBridge(ipc,{manager:{initialize:async()=>{}},isTrustedSender:event=>event?.trusted===true,themeService:{catalog:async()=>{calls++;return{};},apply:async()=>{calls++;return{};}}});
+ for(const channel of [CHANNELS.themeCatalog,CHANNELS.themeApply])await assert.rejects(ipc.handlers.get(channel)({trusted:false},{}),/Untrusted/);
+ assert.equal(calls,0);await ipc.handlers.get(CHANNELS.themeCatalog)({trusted:true});await ipc.handlers.get(CHANNELS.themeApply)({trusted:true},{});assert.equal(calls,2);
+});

electron/plugins/pluginViewHost.cjs

@@ -36,10 +36,19 @@ class PluginViewHost {
     this.contributionService = options.contributionService;
     this.preloadPath = options.preloadPath ?? path.join(__dirname, "runtime", "viewPreload.cjs");
     this.instances = new Map();
+    this.opening = new Map();
+    this.closed = false;
+    this.isLocked = options.isLocked ?? (() => false);
+    this.subscriptions = [];
+    const unsubscribeLock = options.subscribeLock?.((state) => {
+      if (!state.locked) return;
+      for (const opening of this.opening.values()) opening.cancelled = true;
+      for (const instanceId of [...this.instances.keys()]) void this.close(instanceId, undefined, "app-locked");
+    });
+    this.subscriptions.push({ dispose: () => unsubscribeLock?.() });
     this.byWebContentsId = new Map();
     this.closeListeners = new Set();
     this.environment = { locale: "en", theme: "system", reducedMotion: false, highContrast: false };
-    this.subscriptions = [];
     this.#registerIpc();
     this.subscriptions.push(this.contributionService.onDidPostViewMessage((event) => {
       for (const instance of this.instances.values()) {
@@ -49,10 +58,14 @@ class PluginViewHost {
       }
     }));
     this.subscriptions.push(this.contributionService.onDidChange?.((event) => {
-      if (!["plugin-disabled", "runtime-stopped", "runtime-error", "runtime-quarantined"].includes(event.reason)
-        || !event.pluginId) return;
       for (const instance of [...this.instances.values()]) {
-        if (instance.pluginId === event.pluginId) void this.close(instance.instanceId, undefined, event.reason);
+        if (["plugin-disabled", "runtime-stopped", "runtime-error", "runtime-quarantined"].includes(event.reason)
+          && instance.pluginId === event.pluginId) {
+          void this.close(instance.instanceId, undefined, event.reason);
+        } else if (["vault-page", "terminal-sidebar"].includes(instance.location)) {
+          try { this.contributionService.assertViewActivationCurrent(instance.activation, { context: instance.context }); }
+          catch { void this.close(instance.instanceId, undefined, "contribution-unavailable"); }
+        }
       }
     }));
   }
@@ -115,10 +128,45 @@ class PluginViewHost {
 
   async open(payload, sender) {
     if (!payload || typeof payload !== "object") throw new TypeError("Plugin view request is invalid");
+    const owner = this.electron.BrowserWindow.fromWebContents(sender);
+    if (this.closed || this.isLocked() || !owner || owner.isDestroyed()) throw new Error("Plugin view owner is unavailable");
+    const instanceId = typeof payload.instanceId === "string" && payload.instanceId.length <= 128
+      ? payload.instanceId : randomUUID();
+    if (this.instances.has(instanceId) || this.opening.has(instanceId)) throw new Error(`Plugin view already exists: ${instanceId}`);
+    const opening = { owner, cancelled: false };
+    const cancel = () => { opening.cancelled = true; };
+    const rendererGone = () => { void this.close(instanceId, undefined, "owner-renderer-gone"); };
+    const navigate = (details, _url, isInPlace, isMainFrame) => {
+      if ((details?.isMainFrame ?? isMainFrame) !== false && (details?.isSameDocument ?? isInPlace) !== true) rendererGone();
+    };
+    const cleanupOwner = () => {
+      sender.removeListener?.("render-process-gone", rendererGone);
+      sender.removeListener?.("did-start-navigation", navigate);
+    };
+    this.opening.set(instanceId, opening);
+    owner.once?.("closed", cancel);
+    sender.on?.("render-process-gone", rendererGone);
+    sender.on?.("did-start-navigation", navigate);
+    try { return await this.#open({ ...payload, instanceId }, sender, opening); }
+    finally {
+      owner.removeListener?.("closed", cancel);
+      const instance = this.instances.get(instanceId);
+      if (instance) instance.cleanupOwner = cleanupOwner;
+      else cleanupOwner();
+      if (this.opening.get(instanceId) === opening) this.opening.delete(instanceId);
+    }
+  }
+
+  #assertOpening(opening) {
+    if (this.closed || this.isLocked() || opening.cancelled || opening.owner.isDestroyed()) throw new Error("Plugin view opening was cancelled");
+  }
+
+  async #open(payload, sender, opening) {
     const { plugin, view, identity } = await this.contributionService.activateView(
       payload.viewId,
       { context: payload.context },
     );
+    this.#assertOpening(opening);
     const activation = Object.freeze({
       pluginId: plugin.id,
       pluginVersion: plugin.activeVersion,
@@ -135,6 +183,7 @@ class PluginViewHost {
       : randomUUID();
     if (this.instances.has(instanceId)) throw new Error(`Plugin view already exists: ${instanceId}`);
     const packageRoot = await this.packageStore.preparePackageRoot(plugin);
+    this.#assertOpening(opening);
     this.contributionService.assertViewActivationCurrent(activation, { context: payload.context });
     const partition = `netcatty-plugin-view-${randomUUID()}`;
     const pluginSession = this.electron.session.fromPartition(partition, { cache: false });
@@ -183,12 +232,22 @@ class PluginViewHost {
         if (url !== registration.url) event.preventDefault();
       });
       contents.on("will-attach-webview", (event) => event.preventDefault());
+      contents.once("render-process-gone", () => { void this.close(instanceId, undefined, "view-renderer-gone"); });
+      if (["vault-page", "terminal-sidebar"].includes(view.location)) contents.on("before-input-event", (event, input) => {
+        if (input.type === "keyDown" && input.key === "Escape" && !input.control && !input.meta && !input.alt && !input.shift) {
+          event.preventDefault();
+          void this.close(instanceId, undefined, "host-escape");
+        }
+      });
       const ownerClosed = () => { void this.close(instanceId, undefined, "owner-closed"); };
       const instance = {
         instanceId,
         pluginId: plugin.id,
         viewId: view.id,
         scopeId,
+        location: view.location,
+        activation,
+        context: structuredClone(payload.context ?? {}),
         owner,
         ownerClosed,
         view: contentsView,
@@ -197,8 +256,13 @@ class PluginViewHost {
         sessionRegistration,
         state: "opening",
         attached: false,
+        visible: !["vault-page", "terminal-sidebar"].includes(view.location),
       };
       this.instances.set(instanceId, instance);
+      contents.on("focus", () => {
+        if (this.instances.get(instanceId) !== instance || instance.state !== "open") return;
+        try { owner.webContents?.send("netcatty:plugins:view-focused", { instanceId }); } catch {}
+      });
       this.byWebContentsId.set(contents.id, instance);
       owner.once?.("closed", ownerClosed);
       contents.once("destroyed", () => { void this.close(instanceId, undefined, "contents-destroyed"); });
@@ -208,6 +272,10 @@ class PluginViewHost {
         || owner.isDestroyed() || contents.isDestroyed()) {
         throw new Error("Plugin view ownership changed while opening");
       }
+      this.#assertOpening(opening);
+      // Embedded pages start hidden until the trusted renderer checks host
+      // dialogs/lock/popovers. A late open must never cover a security surface.
+      if (["vault-page", "terminal-sidebar"].includes(view.location)) contentsView.setVisible(false);
       owner.contentView.addChildView(contentsView);
       instance.attached = true;
       contentsView.setBounds(normalizeBounds(payload.bounds));
@@ -232,7 +300,17 @@ class PluginViewHost {
   setVisible(instanceId, visible, sender) {
     if (typeof visible !== "boolean") throw new TypeError("Plugin view visibility must be a boolean");
     const instance = this.#ownedInstance(instanceId, sender);
+    if (visible && this.isLocked()) throw new Error("Plugin view owner is unavailable");
+    const rising = visible && !instance.visible;
+    instance.visible = visible;
     instance.view.setVisible(visible);
+    if (rising && instance.location === "vault-page" && instance.owner.isFocused?.()) instance.contents.focus?.();
+  }
+
+  focus(instanceId, sender) {
+    const instance = this.#ownedInstance(instanceId, sender);
+    if (!instance.visible || this.isLocked() || instance.owner.isFocused?.() !== true) return;
+    instance.contents.focus?.();
   }
 
   async postMessage(instanceId, message, sender) {
@@ -250,11 +328,17 @@ class PluginViewHost {
   }
 
   async close(instanceId, sender, reason = sender ? "renderer-requested" : "host-requested") {
+    const opening = this.opening.get(instanceId);
+    if (opening) {
+      if (sender && this.electron.BrowserWindow.fromWebContents(sender) !== opening.owner) throw new Error("Untrusted plugin view owner");
+      opening.cancelled = true;
+    }
     const instance = this.instances.get(instanceId);
     if (!instance) return;
     if (sender) this.#ownedInstance(instanceId, sender);
     this.instances.delete(instanceId);
     this.byWebContentsId.delete(instance.contents.id);
+    try { instance.cleanupOwner?.(); } catch {}
     try { instance.owner.removeListener?.("closed", instance.ownerClosed); } catch {}
     if (instance.attached) {
       try { instance.owner.contentView.removeChildView(instance.view); } catch {}
@@ -279,6 +363,8 @@ class PluginViewHost {
   }
 
   async shutdown() {
+    this.closed = true;
+    for (const opening of this.opening.values()) opening.cancelled = true;
     await Promise.all([...this.instances.keys()].map((instanceId) => this.close(instanceId)));
     for (const subscription of this.subscriptions.splice(0)) subscription?.dispose?.();
     this.closeListeners.clear();

electron/plugins/pluginViewHost.test.cjs

@@ -25,6 +25,7 @@ function fixture(options = {}) {
       if (options.loadURL) await options.loadURL(this);
     }
     send(channel, payload) { this.sent.push([channel, payload]); }
+    focus() { this.emit("focus"); }
     isDestroyed() { return this.destroyed; }
     close() { this.destroyed = true; this.emit("destroyed"); }
   }
@@ -87,9 +88,10 @@ function fixture(options = {}) {
     onDidPostViewMessage(listener) { viewListener = listener; return { dispose() {} }; },
     onDidChange(listener) { changeListener = listener; return { dispose() {} }; },
     async activateView() {
+      await options.activateView?.();
       return {
         plugin: { id: "com.example.view", activeVersion: "1.0.0" },
-        view: { id: "com.example.view.panel", entry: "view.html", location: "aside" },
+        view: { id: "com.example.view.panel", entry: "view.html", location: options.location ?? "aside" },
         identity: { runtimeId: "runtime-view-1", pluginVersion: "1.0.0" },
       };
     },
@@ -121,6 +123,8 @@ function fixture(options = {}) {
       setViewState(pluginId, viewId, scopeId, value) { state.set(`${pluginId}:${viewId}:${scopeId}`, value); },
     },
     contributionService,
+    isLocked: options.isLocked,
+    subscribeLock: options.subscribeLock,
     preloadPath: "/runtime/viewPreload.cjs",
   });
   function createOwner() {
@@ -131,7 +135,7 @@ function fixture(options = {}) {
       addChildView(view) { owner.children.push(view); },
       removeChildView(view) { owner.children = owner.children.filter((entry) => entry !== view); },
     };
-    const sender = {};
+    const sender = new EventEmitter();
     senderOwners.set(sender, owner);
     return { owner, sender };
   }
@@ -341,3 +345,132 @@ test("view cleanup failures cannot suppress owner removal or the renderer close
     reason: "renderer-requested",
   }]);
 });
+
+test("Vault pages start hidden and are withdrawn when their current contribution is no longer available", async () => {
+  const value = fixture({ location: "vault-page" });
+  const { owner, sender } = value.createOwner();
+  const result = await value.host.open({ viewId: "com.example.view.panel", scopeId: "window-1:vault-page" }, sender);
+  assert.equal(owner.children.length, 1);
+  assert.equal(value.views[0].visible, false, "host modal checks precede native visibility");
+  value.host.setVisible(result.instanceId, true, sender);
+  assert.equal(value.views[0].visible, true);
+  value.setActivationCurrent(false);
+  value.changeListener()({ reason: "context-key-changed" });
+  assert.equal(owner.children.length, 0);
+  assert.equal(value.views[0].webContents.destroyed, true);
+  await value.host.shutdown();
+});
+
+test("closing a reserved owner instance cancels activation before any native page is constructed", async () => {
+  let release;
+  const gate = new Promise((resolve) => { release = resolve; });
+  const value = fixture({ location: "vault-page", activateView: () => gate });
+  const { owner, sender } = value.createOwner();
+  const other = value.createOwner();
+  const opening = value.host.open({ viewId: "com.example.view.panel", scopeId: "window-1:vault-page", instanceId: "reserved-page" }, sender);
+  await assert.rejects(value.host.close("reserved-page", other.sender), /Untrusted/);
+  await value.host.close("reserved-page", sender);
+  release();
+  await assert.rejects(opening, /cancelled/);
+  assert.equal(value.views.length, 0);
+  assert.equal(owner.children.length, 0);
+  assert.equal(value.host.opening.size, 0);
+  await value.host.shutdown();
+});
+
+test("app lock closes attached pages and cancels pending opens, with subscription cleanup", async () => {
+  let listener, locked = false, disposed = 0;
+  const value = fixture({ location: "vault-page", isLocked: () => locked,
+    subscribeLock(fn) { listener = fn; return () => { disposed++; }; } });
+  const { owner, sender } = value.createOwner();
+  const result = await value.host.open({ viewId: "com.example.view.panel", scopeId: "window-1:vault-page" }, sender);
+  locked = true; listener({ locked: true });
+  assert.equal(owner.children.length, 0);
+  assert.equal(value.views[0].webContents.destroyed, true);
+  await assert.rejects(value.host.open({ viewId: "com.example.view.panel", scopeId: "window-1:vault-page" }, sender), /unavailable/);
+  assert.throws(() => value.host.setVisible(result.instanceId, true, sender));
+  await value.host.shutdown();
+  assert.equal(disposed, 1);
+});
+
+test("browser Scratchpad saves, reopens and clears only its own view state through the real host IPC", async () => {
+  const { readFile } = require("node:fs/promises");
+  const path = require("node:path");
+  const { JSDOM } = require("jsdom");
+  const { VIEW_CHANNELS } = require("./pluginViewHost.cjs");
+  const html = await readFile(path.join(__dirname, "../../examples/plugins/vault-scratchpad/page.html"), "utf8");
+  const script = await readFile(path.join(__dirname, "../../examples/plugins/vault-scratchpad/page.js"), "utf8");
+  const value = fixture({ location: "vault-page" });
+  const { sender } = value.createOwner();
+  async function open(scopeId) {
+    const result = await value.host.open({ viewId: "com.example.view.panel", scopeId }, sender);
+    const contents = value.host.instances.get(result.instanceId).contents;
+    const dom = new JSDOM(html, { runScripts: "outside-only" });
+    dom.window.netcattyView = {
+      getState: async () => value.ipcHandlers.get(VIEW_CHANNELS.getState)({ sender: contents }),
+      setState: async (state) => value.ipcHandlers.get(VIEW_CHANNELS.setState)({ sender: contents }, structuredClone(state)),
+    };
+    dom.window.eval(script);
+    await new Promise((resolve) => setImmediate(resolve));
+    return { dom, document: dom.window.document, id: result.instanceId, contents };
+  }
+  const first = await open("window-1:vault-page");
+  first.document.getElementById("draft").value = "synthetic private draft";
+  first.document.getElementById("save").click();
+  await new Promise((resolve) => setImmediate(resolve));
+  assert.match(first.document.getElementById("status").textContent, /saved/);
+  await value.host.close(first.id, sender); first.dom.window.close();
+  const separate = await open("window-2:vault-page");
+  assert.equal(separate.document.getElementById("draft").value, "", "a different host-owned state scope does not inherit this draft");
+  const reopened = await open("window-1:vault-page");
+  assert.equal(reopened.document.getElementById("draft").value, "synthetic private draft");
+  reopened.document.getElementById("clear").click();
+  await new Promise((resolve) => setImmediate(resolve));
+  assert.equal(reopened.document.getElementById("draft").value, "");
+  const cleared = await open("window-1:vault-page");
+  assert.equal(cleared.document.getElementById("draft").value, "");
+  await value.host.shutdown();
+  assert.throws(() => value.ipcHandlers.get(VIEW_CHANNELS.getState)({ sender: reopened.contents }), /Untrusted/);
+  for (const panel of [separate, reopened, cleared]) panel.dom.window.close();
+});
+
+test("host reload, host/view renderer exit, and host Escape close embedded pages", async () => {
+  for (const action of ["reload", "host-exit", "view-exit", "escape"]) {
+    const value = fixture({ location: "vault-page" });
+    const { sender, owner } = value.createOwner();
+    const opened = await value.host.open({ viewId: "com.example.view.panel", scopeId: "window-1:vault-page" }, sender);
+    const contents = value.views[0].webContents;
+    sender.emit("did-start-navigation", { isMainFrame: true, isSameDocument: true });
+    assert.equal(owner.children.length, 1);
+    if (action === "reload") sender.emit("did-start-navigation", { isMainFrame: true, isSameDocument: false });
+    if (action === "host-exit") sender.emit("render-process-gone");
+    if (action === "view-exit") contents.emit("render-process-gone");
+    if (action === "escape") {
+      let prevented = false;
+      contents.emit("before-input-event", { preventDefault() { prevented = true; } }, { type: "keyDown", key: "Escape" });
+      assert.equal(prevented, true);
+    }
+    assert.equal(owner.children.length, 0, action);
+    assert.equal(value.host.instances.has(opened.instanceId), false, action);
+    assert.equal(sender.listenerCount("render-process-gone"), 0, action);
+    await value.host.shutdown();
+  }
+});
+
+test("sidebar native focus is explicit, owner-bound and cannot raise a hidden or locked page", async () => {
+  let locked = false;
+  const value = fixture({ location: "terminal-sidebar", isLocked: () => locked });
+  const { owner, sender } = value.createOwner(); const other = value.createOwner();
+  const events = [];
+  sender.send = (channel, event) => events.push({ channel, event }); owner.webContents = sender; owner.isFocused = () => true;
+  const { instanceId } = await value.host.open({ viewId: "com.example.view.panel", scopeId: "window-1:terminal-sidebar" }, sender);
+  assert.equal(value.views[0].visible, false);
+  value.host.focus(instanceId, sender); assert.deepEqual(events, []);
+  value.host.setVisible(instanceId, true, sender); assert.deepEqual(events, [], "revealing multiple panes does not focus each one");
+  assert.throws(() => value.host.focus(instanceId, other.sender), /another window/i);
+  value.host.focus(instanceId, sender);
+  assert.deepEqual(events, [{ channel: "netcatty:plugins:view-focused", event: { instanceId } }]);
+  locked = true; value.host.focus(instanceId, sender); assert.equal(events.length, 1);
+  locked = false; value.setActivationCurrent(false); value.changeListener()({ reason: "context-key-changed" });
+  assert.equal(owner.children.length, 0); await value.host.shutdown();
+});

electron/plugins/runtime/runtimePeer.mjs

@@ -518,6 +518,10 @@ function createPluginContext(config, client, runtimeApi) {
     },
   };
   const terminals = {
+    shareSelection: (title) => {
+      if (!config.enabledFeatures?.includes("terminal.selection-sharing")) return Promise.reject(new Error("Terminal selection sharing is unsupported"));
+      return interact({ kind: "terminal.selection.read", title });
+    },
     onDidChange: runtimeApi.terminalEvents.event,
   };
   const environment = {

electron/plugins/runtimeSupervisor.cjs

@@ -207,7 +207,7 @@ class RuntimeSupervisor {
 
   async startEnabled() {
     for (const plugin of this.database.listPlugins()) {
-      if (!plugin.enabled || plugin.runtime.quarantinedAt != null) continue;
+      if (!plugin.enabled || plugin.runtime.quarantinedAt != null || plugin.manifest?.main?.data) continue;
       try { await this.start(plugin.id); } catch {}
     }
   }
@@ -240,6 +240,7 @@ class RuntimeSupervisor {
     const plugin = this.database.getActivePlugin(pluginId);
     if (!plugin?.manifest || !plugin.packageRelativePath) throw new Error(`Plugin is not installed: ${pluginId}`);
     if (!plugin.enabled) throw new Error(`Plugin is disabled: ${pluginId}`);
+    if (plugin.manifest.main.data) throw new Error("Static theme packs have no executable runtime");
     if (plugin.runtime.quarantinedAt != null) throw new Error(`Plugin is quarantined: ${pluginId}`);
     const pluginCli = await import("@netcatty/plugin-cli");
     signal.throwIfAborted();

electron/plugins/runtimeSupervisor.test.cjs

@@ -993,3 +993,12 @@ test('new host initializes an exact legacy API plugin with its negotiated legacy
   assert.deepEqual(observed, ['0.1.0-internal']);
   await fixture.supervisor.stop(fixture.manifest.id);
 });
+
+test('data-only themes never create a runtime on startup or explicit start',async(t)=>{
+ const fixture=createFixture(t,()=>{throw new Error('data pack must not execute');});
+ const manifest={...fixture.manifest,main:{data:'theme'},activationEvents:[],features:{required:['appearance.theme-packs']},contributes:{themes:[{id:fixture.manifest.id+'.light',label:'Light',variant:'light',entry:'light.json'}]}};
+ fixture.database.installVersion({pluginId:manifest.id,version:manifest.version,manifest,archiveSha256:'a'.repeat(64),packageRelativePath:'theme'}, {enable:true});
+ await fixture.supervisor.startEnabled();assert.equal(fixture.runtimeOptions.length,0);
+ await assert.rejects(fixture.supervisor.start(manifest.id),/no executable runtime/);assert.equal(fixture.runtimeOptions.length,0);
+ await fixture.supervisor.shutdown();
+});

electron/plugins/terminalSelectionAuthority.cjs

@@ -0,0 +1,67 @@
+"use strict";
+const {randomBytes,createHmac}=require('node:crypto');
+const {createDefinitionValidator}=require('./contractValidator.cjs');
+const {PluginRpcError,RPC_ERRORS}=require('./rpcRouter.cjs');
+const schema=require('./generated/plugin-contract.schema.json');
+const LIMITS=schema.$defs.TerminalSelectionSharingLimits.const;
+const FEATURE=schema.$defs.TerminalSelectionSharingFeature.const;
+const validateTarget=createDefinitionValidator('HostTerminalTarget');
+const fail=(code,message)=>new PluginRpcError(RPC_ERRORS[code],message);
+/** Host-only resource authority. It never stores selected text or an endpoint DTO. */
+class TerminalSelectionAuthority {
+ constructor(options){
+  this.getWindow=options.getWindow??(()=>null);this.getManager=options.getManager??(()=>null);this.clock=options.clock??Date.now;
+  this.key=randomBytes(32);this.target=null;this.handles=new Map();this.listeners=new Set();this.observed=null;this.disposables=[];
+  this.timer=setInterval(()=>this.prune(),1000);this.timer.unref?.();
+ }
+ onDidInvalidate(listener){this.listeners.add(listener);return{dispose:()=>this.listeners.delete(listener)};}
+ invalidate(){this.prune();for(const listener of this.listeners){try{listener();}catch{}}}
+ observe(manager){
+  if(this.observed===manager)return;
+  for(const item of this.disposables)item?.dispose?.();this.disposables=[];this.observed=manager;
+  for(const method of ['onSessionOwned','onSessionClosed','onWorkerExit'])if(typeof manager?.[method]==='function')this.disposables.push(manager[method](()=>this.invalidate()));
+ }
+ setTarget(sender,payload){
+  if(!validateTarget(payload))throw fail('invalidArgument','Invalid selected terminal target');
+  if(!sender || this.getWindow()?.webContents!==sender || sender.isDestroyed?.())throw fail('permissionDenied','Selected terminal belongs to another window');
+  if(this.target?.sender===sender && this.target.sessionId===payload.sessionId)return true;
+  this.target=payload.sessionId?{sender,sessionId:payload.sessionId}:null;this.invalidate();return true;
+ }
+ capture(sender,context){
+  const features=[...(context.manifest?.features?.required??[]),...(context.manifest?.features?.optional??[])];
+  if(!features.includes(FEATURE))throw fail('unsupported','Terminal selection sharing feature was not declared');
+  const manager=this.getManager();this.observe(manager);
+  if(!this.target || this.target.sender!==sender)throw fail('failedPrecondition','Select a live terminal in the main window first');
+  const {sessionId}=this.target;const binding=manager?.getPluginSessionBinding?.(sessionId,sender.id);
+  if(!binding)throw fail('unavailable','Selected terminal has no active owned worker connection');
+  return Object.freeze({sender,manager,sessionId,epoch:binding.epoch,generation:binding.generation,
+   resource:`terminal-session:${sessionId}:window:${sender.id}:worker:${binding.epoch}:generation:${binding.generation}`});
+ }
+ isCurrent(target){
+  if(!target || this.target?.sender!==target.sender || this.target?.sessionId!==target.sessionId || target.sender.isDestroyed?.() || this.getManager()!==target.manager)return false;
+  const current=target.manager.getPluginSessionBinding(target.sessionId,target.sender.id);
+  return !!current && current.epoch===target.epoch && current.generation===target.generation;
+ }
+ assertCurrent(target){if(!this.isCurrent(target))throw fail('cancelled','Selected terminal connection or owner changed');}
+ prune(){for(const [token,entry]of this.handles)if(entry.expiresAt<=this.clock()||!this.isCurrent(entry.target))this.handles.delete(token);}
+ issue(target,context){
+  this.assertCurrent(target);this.prune();
+  if(this.handles.size>=LIMITS.handlesTotal || [...this.handles.values()].filter(e=>e.runtimeId===context.runtimeId).length>=LIMITS.handlesPerRuntime)throw fail('resourceExhausted','Terminal selection handle limit reached');
+  const expiresAt=this.clock()+LIMITS.handleTtlMs,nonce=randomBytes(24).toString('base64url');
+  const signature=createHmac('sha256',this.key).update(JSON.stringify([nonce,target.resource,context.pluginId,context.pluginVersion,context.runtimeId,context.securityPrincipal??null,expiresAt])).digest('base64url');
+  const handle=`${nonce}.${signature}`;
+  this.handles.set(handle,{target,expiresAt,pluginId:context.pluginId,pluginVersion:context.pluginVersion,runtimeId:context.runtimeId,securityPrincipal:context.securityPrincipal});
+  return {handle,expiresAt};
+ }
+ resolve(handle,context){
+  this.prune();const entry=this.handles.get(handle);
+  if(!entry || entry.pluginId!==context.pluginId || entry.pluginVersion!==context.pluginVersion || entry.runtimeId!==context.runtimeId || entry.securityPrincipal!==context.securityPrincipal)throw fail('permissionDenied','Terminal selection handle is unavailable');
+  this.assertCurrent(entry.target);return entry.target;
+ }
+ releaseRuntime(runtimeId){for(const [key,entry]of this.handles)if(entry.runtimeId===runtimeId)this.handles.delete(key);}
+ releasePlugin(pluginId){for(const [key,entry]of this.handles)if(entry.pluginId===pluginId)this.handles.delete(key);}
+ releaseWindow(sender){if(this.target?.sender===sender)this.target=null;this.invalidate();}
+ clearHandles(){this.handles.clear();}
+ shutdown(){clearInterval(this.timer);for(const d of this.disposables)d?.dispose?.();this.handles.clear();this.listeners.clear();this.target=null;this.key.fill(0);}
+}
+module.exports={TerminalSelectionAuthority,FEATURE,LIMITS};

electron/plugins/themeService.cjs

@@ -0,0 +1,220 @@
+"use strict";
+const fs = require("node:fs/promises");
+const { constants } = require("node:fs");
+const path = require("node:path");
+const { createDefinitionValidator } = require("./contractValidator.cjs");
+const { resolveThemePalette } = require("../../domain/pluginThemePack.cjs");
+const { isStaticThemePack } = require("../../domain/pluginRuntimePolicy.cjs");
+const validatePalette = createDefinitionValidator("ThemePackPalette");
+const validateApply = createDefinitionValidator("ThemePackApplyRequest");
+const validateSelection = createDefinitionValidator("ThemePackSelection");
+const limits = require("./generated/plugin-contract.schema.json").$defs
+  .ThemePackLimits.const;
+const key = (ref) =>
+  JSON.stringify([
+    ref.pluginId,
+    ref.themeId,
+    ref.version,
+    ref.digest,
+    ref.variant,
+  ]);
+class PluginThemeService {
+  constructor({ database, packageStore, contributionService }) {
+    Object.assign(this, { database, packageStore });
+    this.generation = 0;
+    this.cache = new Map();
+    this.listeners = new Set();
+    this.tail = Promise.resolve();
+    this.dispose = contributionService?.onDidChange?.((event) => {
+      if (
+        !["initialized", "plugin-enabled", "plugin-disabled"].includes(
+          event.reason,
+        )
+      )
+        return;
+      this.generation++;
+      this.cache.clear();
+      this.emit();
+    });
+  }
+  onDidChange(listener) {
+    this.listeners.add(listener);
+    return () => this.listeners.delete(listener);
+  }
+  emit() {
+    for (const listener of this.listeners) {
+      try {
+        listener();
+      } catch {}
+    }
+  }
+  active(ref) {
+    const p = this.database.getActivePlugin(ref.pluginId);
+    return (
+      p?.enabled &&
+      p.activeVersion === ref.version &&
+      p.archiveSha256 === ref.digest &&
+      p.manifest?.contributes?.themes?.some(
+        (t) => t.id === ref.themeId && t.variant === ref.variant,
+      )
+    );
+  }
+  catalog() {
+    if (!this.pendingCatalog) {
+      const pending = this.readCatalog().finally(() => {
+        if (this.pendingCatalog === pending) this.pendingCatalog = null;
+      });
+      this.pendingCatalog = pending;
+    }
+    return this.pendingCatalog;
+  }
+  async readCatalog(retry = true) {
+    const generation = this.generation,
+      entries = [],
+      diagnostics = [];
+    for (const plugin of this.database.listPlugins()) {
+      if (!plugin.enabled) continue;
+      let packageRoot;
+      for (const theme of plugin.manifest?.contributes?.themes ?? []) {
+        if (entries.length >= limits.catalogEntries) {
+          if (diagnostics.length < 256)
+            diagnostics.push({ pluginId: plugin.id, code: "capacity" });
+          break;
+        }
+        const ref = {
+          pluginId: plugin.id,
+          themeId: theme.id,
+          version: plugin.activeVersion,
+          digest: plugin.archiveSha256,
+          variant: theme.variant,
+        };
+        try {
+          let palette = this.cache.get(key(ref));
+          if (!palette) {
+            const root = (packageRoot ??=
+              await this.packageStore.preparePackageRoot(plugin));
+            const target = path.resolve(root, theme.entry);
+            if (
+              !theme.entry.endsWith(".json") ||
+              !target.startsWith(root + path.sep)
+            )
+              throw new Error("Invalid path");
+            const handle = await fs.open(
+              target,
+              constants.O_RDONLY | constants.O_NOFOLLOW,
+            );
+            try {
+              const stat = await handle.stat();
+              if (!stat.isFile() || stat.size > limits.jsonBytes)
+                throw new Error("Invalid theme size");
+              const bytes = Buffer.alloc(limits.jsonBytes + 1);
+              const { bytesRead } = await handle.read(
+                bytes,
+                0,
+                bytes.length,
+                0,
+              );
+              if (bytesRead > limits.jsonBytes)
+                throw new Error("Invalid theme size");
+              palette = JSON.parse(
+                new TextDecoder("utf-8", { fatal: true }).decode(
+                  bytes.subarray(0, bytesRead),
+                ),
+              );
+            } finally {
+              await handle.close();
+            }
+            if (
+              !validatePalette(palette) ||
+              palette.base !==
+                (theme.variant.endsWith("dark") ? "dark" : "light")
+            )
+              throw new Error("Invalid theme palette");
+            resolveThemePalette(palette);
+            // Only immutable, validated data enters the catalog/cache.
+            palette = JSON.parse(JSON.stringify(palette));
+            if (generation === this.generation && this.active(ref))
+              this.cache.set(key(ref), palette);
+          }
+          if (generation !== this.generation || !this.active(ref)) continue;
+          const label =
+            typeof theme.label === "string"
+              ? theme.label
+              : (theme.label.en ??
+                theme.label.default ??
+                Object.values(theme.label)[0]);
+          entries.push({
+            ref,
+            label,
+            pluginName: plugin.manifest.name,
+            dataOnly: isStaticThemePack(plugin.manifest),
+            palette,
+          });
+        } catch {
+          if (diagnostics.length < 256)
+            diagnostics.push({
+              pluginId: plugin.id,
+              themeId: theme.id,
+              code: "invalid",
+            });
+        }
+      }
+    }
+    // A package change during an async read must never publish an old palette.
+    if (generation !== this.generation) {
+      if (retry) return this.readCatalog(false);
+      throw new Error("Theme packages changed; refresh again");
+    }
+    const selection = this.database.getHostThemeSelection();
+    if (!validateSelection(selection))
+      throw new Error("Invalid saved theme selection");
+    return { selection, entries, diagnostics };
+  }
+  apply(request) {
+    const run = async () => {
+      if (!validateApply(request))
+        throw new TypeError("Invalid theme selection request");
+      const { selection, entries } = await this.catalog();
+      if (selection.revision !== request.expectedRevision)
+        throw new Error("Theme selection changed; refresh before applying");
+      if (request.choice) {
+        const entry = entries.find(
+          (e) => key(e.ref) === key(request.choice.ref),
+        );
+        if (
+          !entry ||
+          entry.palette.base !== request.mode ||
+          !this.active(entry.ref)
+        )
+          throw new Error("Theme is no longer available");
+      }
+      if (selection.revision >= Number.MAX_SAFE_INTEGER)
+        throw new Error("Theme revision exhausted");
+      const next = {
+        ...selection,
+        revision: selection.revision + 1,
+        [request.mode]: request.choice,
+      };
+      // Synchronous active check immediately before the atomic preference/audit write.
+      if (request.choice && !this.active(request.choice.ref))
+        throw new Error("Theme changed before apply");
+      this.database.commitHostThemeSelection(
+        request.expectedRevision,
+        next,
+        request.choice?.ref.pluginId,
+      );
+      this.emit();
+      return this.catalog();
+    };
+    const result = this.tail.then(run);
+    this.tail = result.catch(() => {});
+    return result;
+  }
+  shutdown() {
+    if (typeof this.dispose === "function") this.dispose();
+    else this.dispose?.dispose();
+    this.cache.clear();
+    this.listeners.clear();
+  }
+}
+module.exports = { PluginThemeService };

electron/plugins/themeService.test.cjs

@@ -0,0 +1,168 @@
+"use strict";
+const assert = require("node:assert/strict");
+const test = require("node:test");
+const fs = require("node:fs");
+const path = require("node:path");
+const os = require("node:os");
+const { PluginDatabase } = require("./database.cjs");
+const { PluginThemeService } = require("./themeService.cjs");
+function fixture(t) {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), "netcatty-theme-test-"));
+  const database = new PluginDatabase(path.join(root, "plugins.sqlite"));
+  const manifest = JSON.parse(
+    fs.readFileSync(
+      path.join(
+        __dirname,
+        "../../examples/plugins/forest-theme-pack/netcatty.plugin.json",
+      ),
+      "utf8",
+    ),
+  );
+  const install = (version = "0.1.0", digest = "a".repeat(64)) =>
+    database.installVersion(
+      {
+        pluginId: manifest.id,
+        version,
+        manifest: { ...manifest, version },
+        archiveSha256: digest,
+        packageRelativePath: "theme",
+      },
+      { enable: true },
+    );
+  install();
+  for (const mode of ["light", "dark"])
+    fs.copyFileSync(
+      path.join(
+        __dirname,
+        "../../examples/plugins/forest-theme-pack",
+        mode + ".json",
+      ),
+      path.join(root, mode + ".json"),
+    );
+  let change;
+  const packageStore = {
+    async preparePackageRoot() {
+      return root;
+    },
+  };
+  const service = new PluginThemeService({
+    database,
+    packageStore,
+    contributionService: {
+      onDidChange(listener) {
+        change = listener;
+        return () => {};
+      },
+    },
+  });
+  t.after(() => {
+    service.shutdown();
+    database.close();
+    fs.rmSync(root, { recursive: true, force: true });
+  });
+  return {
+    root,
+    database,
+    service,
+    packageStore,
+    install,
+    change: () => change({ reason: "plugin-disabled" }),
+  };
+}
+test("data-only themes enumerate without runtime, apply with CAS and fixed audit, retain missing preference after disable", async (t) => {
+  const f = fixture(t),
+    catalog = await f.service.catalog();
+  assert.equal(catalog.entries.length, 2);
+  assert.ok(catalog.entries.every((e) => e.dataOnly));
+  assert.equal(catalog.selection.revision, 0);
+  const ref = catalog.entries[0].ref;
+  const applied = await f.service.apply({
+    expectedRevision: 0,
+    mode: "light",
+    choice: { ref },
+  });
+  assert.equal(applied.selection.light.ref.digest, "a".repeat(64));
+  await assert.rejects(
+    f.service.apply({ expectedRevision: 0, mode: "light", choice: { ref } }),
+    /changed/,
+  );
+  assert.deepEqual(f.database.listSecurityAudit(ref.pluginId)[0].details, {
+    revision: 1,
+    action: "apply",
+  });
+  f.database.setEnabled(ref.pluginId, false);
+  f.change();
+  const disabled = await f.service.catalog();
+  assert.equal(disabled.entries.length, 0);
+  assert.deepEqual(disabled.selection.light, { ref });
+  await assert.rejects(
+    f.service.apply({ expectedRevision: 1, mode: "light", choice: { ref } }),
+    /no longer available/,
+  );
+  const restored = await f.service.apply({
+    expectedRevision: 1,
+    mode: "light",
+    choice: null,
+  });
+  assert.equal(restored.selection.light, null);
+});
+test("palette validation rejects unsupported values, low contrast, mode mismatch and bounded oversize", async (t) => {
+  const f = fixture(t);
+  for (const palette of [
+    { formatVersion: 1, base: "light", colors: { accent: "var(--x)" } },
+    { formatVersion: 1, base: "light", colors: { foreground: "#ffffff" } },
+    { formatVersion: 1, base: "light", colors: { muted: "#000000", mutedForeground: "#ffffff" } },
+    { formatVersion: 1, base: "dark", colors: { accent: "#86efac" } },
+    " ".repeat(65537),
+  ]) {
+    fs.writeFileSync(
+      path.join(f.root, "light.json"),
+      typeof palette === "string" ? palette : JSON.stringify(palette),
+    );
+    f.change();
+    const catalog = await f.service.catalog();
+    assert.equal(catalog.entries.length, 1);
+    assert.equal(catalog.diagnostics[0].code, "invalid");
+  }
+});
+test("replacement during an awaited package read cannot publish or apply the old identity", async (t) => {
+  const f = fixture(t);
+  const before = await f.service.catalog(),
+    ref = before.entries[0].ref;
+  f.change();
+  let once = true;
+  f.packageStore.preparePackageRoot = async () => {
+    if (once) {
+      once = false;
+      f.install("0.1.1", "b".repeat(64));
+      f.change();
+    }
+    return f.root;
+  };
+  const catalog = await f.service.catalog();
+  assert.ok(catalog.entries.every((e) => e.ref.version === "0.1.1"));
+  await assert.rejects(
+    f.service.apply({ expectedRevision: 0, mode: "light", choice: { ref } }),
+    /no longer available/,
+  );
+});
+test("preference and audit roll back together on audit failure and survive schema-3 migration", async (t) => {
+  const f = fixture(t),
+    ref = (await f.service.catalog()).entries[0].ref;
+  f.database.db.exec(
+    "CREATE TRIGGER reject_theme_audit BEFORE INSERT ON plugin_security_audit BEGIN SELECT RAISE(ABORT,'synthetic audit failure'); END",
+  );
+  await assert.rejects(
+    f.service.apply({ expectedRevision: 0, mode: "light", choice: { ref } }),
+    /synthetic audit failure/,
+  );
+  assert.equal(f.database.getHostThemeSelection().revision, 0);
+  f.database.db.exec("DROP TRIGGER reject_theme_audit");
+  const file = path.join(f.root, "v3.sqlite");
+  const old = new PluginDatabase(file);
+  old.db.exec("DROP TABLE plugin_host_preferences; PRAGMA user_version=3");
+  old.close();
+  const migrated = new PluginDatabase(file);
+  assert.equal(migrated.getHostThemeSelection().revision, 0);
+  migrated.close();
+});

electron/plugins/viewThemeExamples.test.cjs

@@ -0,0 +1,67 @@
+const assert = require("node:assert/strict");
+const test = require("node:test");
+const fs = require("node:fs");
+const path = require("node:path");
+const { JSDOM } = require("jsdom");
+test("official view examples consume initial/live host HSL tokens and dispose subscriptions", () => {
+  for (const name of [
+    "starter-netcatty",
+    "vault-scratchpad",
+    "session-scratchpad",
+  ]) {
+    const root = path.join(__dirname, "../../examples/plugins", name),
+      dom = new JSDOM("<!doctype html><html></html>", {
+        runScripts: "outside-only",
+      });
+    let listener,
+      disposed = 0,
+      subscriptions = 0;
+    dom.window.netcattyView = {
+      onDidChangeEnvironment(fn) {
+        subscriptions++;
+        listener = fn;
+        return {
+          dispose() {
+            disposed++;
+          },
+        };
+      },
+    };
+    dom.window.eval(fs.readFileSync(path.join(root, "theme.js"), "utf8"));
+    listener({
+      theme: "light",
+      themeTokens: {
+        "--primary": "120 50% 30%",
+        "--background": "0 0% 100%",
+        "--unsupported": "ignored",
+      },
+    });
+    assert.equal(
+      dom.window.document.documentElement.style.getPropertyValue("--primary"),
+      "120 50% 30%",
+    );
+    assert.equal(
+      dom.window.document.documentElement.style.getPropertyValue(
+        "--unsupported",
+      ),
+      "",
+    );
+    listener({
+      theme: "dark",
+      reducedMotion: true,
+      themeTokens: { "--primary": "120 50% 70%" },
+    });
+    assert.equal(dom.window.document.documentElement.style.colorScheme, "dark");
+    assert.equal(
+      dom.window.document.documentElement.style.getPropertyValue(
+        "--background",
+      ),
+      "",
+    );
+    dom.window.dispatchEvent(new dom.window.Event("pagehide"));
+    assert.equal(disposed, 1);
+    dom.window.dispatchEvent(new dom.window.Event("pageshow"));
+    assert.equal(subscriptions, 2);
+    dom.window.close();
+  }
+});

electron/preload/api.cjs

@@ -122,6 +122,14 @@ function createPreloadApi(ctx) {
   }),
   restartPlugin: (pluginId) => ipcRenderer.invoke("netcatty:plugins:restart", { pluginId }),
   uninstallPlugin: (pluginId) => ipcRenderer.invoke("netcatty:plugins:uninstall", { pluginId }),
+  setPluginTerminalTarget: (target) => ipcRenderer.invoke("netcatty:plugins:terminal-target", target),
+  getPluginThemes: () => ipcRenderer.invoke("netcatty:plugins:theme-catalog"),
+  applyPluginTheme: (request) => ipcRenderer.invoke("netcatty:plugins:theme-apply", request),
+  onPluginThemesChanged: (callback) => {
+    const listener = () => callback();
+    ipcRenderer.on("netcatty:plugins:themes-changed", listener);
+    return () => ipcRenderer.removeListener("netcatty:plugins:themes-changed", listener);
+  },
   getPluginContributions: (options) => ipcRenderer.invoke("netcatty:plugins:contributions", options ?? {}),
   getPluginBrandIcon: (pluginId) => ipcRenderer.invoke("netcatty:plugins:brand-icon", { pluginId }),
   getPluginContributionIcon: (pluginId, icon) => ipcRenderer.invoke("netcatty:plugins:contribution-icon", { pluginId, icon }),
@@ -270,6 +278,7 @@ function createPreloadApi(ctx) {
   },
   openPluginView: (payload) => ipcRenderer.invoke("netcatty:plugins:open-view", payload),
   closePluginView: (instanceId) => ipcRenderer.invoke("netcatty:plugins:close-view", { instanceId }),
+  focusPluginView: (payload) => ipcRenderer.invoke("netcatty:plugins:focus-view", payload),
   setPluginViewBounds: (instanceId, bounds) => ipcRenderer.invoke("netcatty:plugins:set-view-bounds", { instanceId, bounds }),
   setPluginViewVisibility: (instanceId, visible) => ipcRenderer.invoke("netcatty:plugins:set-view-visibility", {
     instanceId,
@@ -290,6 +299,11 @@ function createPreloadApi(ctx) {
     ipcRenderer.on("netcatty:plugins:view-closed", listener);
     return () => ipcRenderer.removeListener("netcatty:plugins:view-closed", listener);
   },
+  onPluginViewFocused: (callback) => {
+    const listener = (_event, payload) => callback(payload);
+    ipcRenderer.on("netcatty:plugins:view-focused", listener);
+    return () => ipcRenderer.removeListener("netcatty:plugins:view-focused", listener);
+  },
   getPluginScopeCatalog: () => ipcRenderer.invoke("netcatty:plugins:get-scope-catalog"),
   setPluginScopeCatalog: (catalog) => ipcRenderer.invoke("netcatty:plugins:set-scope-catalog", catalog),
   onPluginScopeCatalogChanged: (callback) => {

examples/plugins/forest-theme-pack/README.md

@@ -0,0 +1,5 @@
+# Forest Themes
+
+A data-only light/dark host color pack. No JavaScript entrypoint, runtime activation, permissions, network, fonts or external assets. Install and enable through Settings > Plugins; select the current light/dark variant in Appearance > Plugin themes. Preview is local to this window; Apply saves only this device’s host selection. Cancel preview or Restore default returns to host-owned colors. Personal accent and fonts remain authoritative.
+
+Disable, uninstall, update or integrity failure makes an applied version unavailable and falls back to a safe same-mode palette. A changed package is not automatically applied. High-contrast system preferences use the fixed host palette. Terminal palettes and font/density/icon/background changes are not part of this first color-pack contract.

examples/plugins/forest-theme-pack/dark.json

@@ -0,0 +1,19 @@
+{
+  "formatVersion": 1,
+  "base": "dark",
+  "colors": {
+    "background": "#101c16",
+    "foreground": "#f0f9f3",
+    "card": "#17281e",
+    "cardForeground": "#f0f9f3",
+    "popover": "#17281e",
+    "popoverForeground": "#f0f9f3",
+    "secondary": "#21392b",
+    "secondaryForeground": "#f0f9f3",
+    "muted": "#1b3024",
+    "mutedForeground": "#c4dbc9",
+    "accent": "#86efac",
+    "border": "#82a98d",
+    "input": "#82a98d"
+  }
+}

examples/plugins/forest-theme-pack/light.json

@@ -0,0 +1,19 @@
+{
+  "formatVersion": 1,
+  "base": "light",
+  "colors": {
+    "background": "#f4faf6",
+    "foreground": "#16251c",
+    "card": "#ffffff",
+    "cardForeground": "#16251c",
+    "popover": "#ffffff",
+    "popoverForeground": "#16251c",
+    "secondary": "#dcebe1",
+    "secondaryForeground": "#16251c",
+    "muted": "#e7f2eb",
+    "mutedForeground": "#324b3b",
+    "accent": "#166534",
+    "border": "#527360",
+    "input": "#527360"
+  }
+}

examples/plugins/forest-theme-pack/netcatty.plugin.json

@@ -0,0 +1,46 @@
+{
+  "manifestVersion": 1,
+  "id": "com.netcatty.forest-themes",
+  "name": "forest-themes",
+  "displayName": {
+    "en": "Forest Themes",
+    "zh-CN": "森林主题"
+  },
+  "version": "0.1.0",
+  "publisher": "netcatty",
+  "license": "GPL-3.0-or-later",
+  "engines": {
+    "netcatty": ">=0.0.0",
+    "api": ">=0.1.0-internal.1 <0.2.0"
+  },
+  "features": {
+    "required": [
+      "appearance.theme-packs"
+    ]
+  },
+  "main": {
+    "data": "theme"
+  },
+  "contributes": {
+    "themes": [
+      {
+        "id": "com.netcatty.forest-themes.light",
+        "label": {
+          "en": "Forest Light",
+          "zh-CN": "森林浅色"
+        },
+        "variant": "light",
+        "entry": "light.json"
+      },
+      {
+        "id": "com.netcatty.forest-themes.dark",
+        "label": {
+          "en": "Forest Dark",
+          "zh-CN": "森林深色"
+        },
+        "variant": "dark",
+        "entry": "dark.json"
+      }
+    ]
+  }
+}

examples/plugins/session-scratchpad/README.md

@@ -0,0 +1,32 @@
+# Session Scratchpad
+
+Fixture ID: `com.netcatty.session-scratchpad`, version `0.1.1`.
+Required permission: **views**, for this plugin's own pages only. Required
+feature: `views.terminal-sidebar`. No terminal/session read, clipboard, network,
+Vault, filesystem, credential or shell permission is requested.
+
+```sh
+node packages/plugin-cli/dist/cli.js pack examples/plugins/session-scratchpad --out /tmp/session-scratchpad.ncpkg
+```
+
+Import disabled through normal Settings, inspect and enable. Parent native QA
+must obtain a fixture-specific own-views approval; no previous plugin's grant
+applies. Use only an explicitly approved synthetic terminal target, without
+entering commands or connecting to real hosts for this page check.
+
+In an open terminal, choose **Extension pages** in its toolbar, then **Session
+scratchpad**. This is a real existing side-panel pane. Save synthetic text,
+split beside a built-in tool, resize/move/magnify, return and reopen. The host
+keeps this page's state in a placement/session bucket; the page never receives
+the session ID, endpoint, cwd, title, history, selection or terminal output.
+This is plugin-owned text, not a Vault Note, and is not automatically synced.
+
+For a separately approved second synthetic terminal/workspace focus target,
+verify that navigation closes the old native view and uses a separate draft
+bucket. Switch back to verify the saved first draft. Clear it to verify
+deletion. Close the pane, press Escape, disable/revoke, and verify cleanup.
+Settings/permission dialogs and overlapping menus must stay above native
+content. No new native target or persistent grant should be inferred from this
+README; parent coordinates the exact test and records source SHA/package hash.
+
+The page subscribes to `window.netcattyView.onDidChangeEnvironment()` in `theme.js`. It follows the seven public HSL theme variables, including accent changes, without reading host settings or DOM. The subscription is disposed on page hide.

examples/plugins/session-scratchpad/browser.js

@@ -0,0 +1 @@
+export default { activate() {} };

examples/plugins/session-scratchpad/netcatty.plugin.json

@@ -0,0 +1,46 @@
+{
+  "manifestVersion": 1,
+  "id": "com.netcatty.session-scratchpad",
+  "name": "session-scratchpad",
+  "displayName": {
+    "en": "Session Scratchpad",
+    "zh-CN": "会话草稿板"
+  },
+  "version": "0.1.1",
+  "publisher": "netcatty",
+  "license": "GPL-3.0-or-later",
+  "engines": {
+    "netcatty": ">=0.0.0",
+    "api": ">=0.1.0-internal.1 <0.2.0"
+  },
+  "features": {
+    "required": [
+      "views.terminal-sidebar"
+    ]
+  },
+  "main": {
+    "browser": "browser.js"
+  },
+  "activationEvents": [
+    "onView:com.netcatty.session-scratchpad.page"
+  ],
+  "permissions": {
+    "required": [
+      "views"
+    ]
+  },
+  "contributes": {
+    "views": [
+      {
+        "id": "com.netcatty.session-scratchpad.page",
+        "title": {
+          "en": "Session scratchpad",
+          "zh-CN": "会话草稿板"
+        },
+        "location": "terminal-sidebar",
+        "entry": "page.html",
+        "order": 10
+      }
+    ]
+  }
+}

examples/plugins/session-scratchpad/page.css

@@ -0,0 +1,20 @@
+:root { color-scheme: light dark; font: 14px/1.6 system-ui, sans-serif; }
+* { box-sizing: border-box; }
+body { margin: 0; padding: 24px; background: hsl(var(--background, 0 0% 100%)); color: hsl(var(--foreground, 222 47% 12%)); }
+main { min-width: 0; overflow-wrap: anywhere; max-width: 720px; margin: auto; }
+h1 { margin: 0 0 8px; font-size: 22px; line-height: 1.3; letter-spacing: -.02em; }
+p { color: hsl(var(--muted-foreground, 215 20% 35%)); }
+label { display: block; font-weight: 600; }
+textarea { display: block; width: 100%; min-width: 0; resize: vertical; min-height: 140px; margin: 10px 0 16px; padding: 12px; border: 1px solid hsl(var(--border, 215 20% 75%)); border-radius: 10px; background: hsl(var(--muted, 210 20% 96%)); color: inherit; font: inherit; }
+button { padding: 8px 14px; margin: 0 8px 8px 0; border: 1px solid hsl(var(--border, 215 20% 75%)); border-radius: 8px; background: hsl(var(--background, 0 0% 100%)); color: inherit; font: inherit; font-weight: 500; cursor: pointer; }
+#save, #greet { border-color: transparent; background: hsl(var(--primary, 221 83% 45%)); color: hsl(var(--primary-foreground, 0 0% 100%)); }
+button:hover:not(:disabled) { filter: brightness(.96); }
+button:disabled { opacity: .5; cursor: default; }
+button:focus-visible, textarea:focus-visible { outline: 2px solid hsl(var(--primary, 221 83% 45%)); outline-offset: 3px; }
+#status { min-height: 1.5em; font-size: 12px; }
+#result { white-space: pre-wrap; overflow-wrap: anywhere; padding: 16px; border-radius: 10px; background: hsl(var(--muted, 210 20% 96%)); min-height: 48px; }
+.eyebrow { color: hsl(var(--muted-foreground, 215 20% 35%)); font-size: 11px; letter-spacing: .1em; }
+@media (max-width: 360px) { body { padding: 16px; } }
+@media (forced-colors: active) { button, textarea { border: 1px solid ButtonText; } }
+
+@media (prefers-color-scheme: dark) { :root { --background: 221 39% 11%; --foreground: 210 20% 98%; --muted: 219 27% 21%; --muted-foreground: 220 13% 91%; --border: 218 11% 65%; --primary: 213 97% 87%; --primary-foreground: 221 39% 11%; } }

examples/plugins/session-scratchpad/page.html

@@ -0,0 +1,7 @@
+<!doctype html>
+<html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
+<title>Session Scratchpad</title><link rel="stylesheet" href="page.css"></head>
+<body><main><h1>Session scratchpad</h1><p>This page stores only text you type here, in this plugin's own view state. It cannot read Vault hosts, notes, credentials, sessions or the clipboard.</p>
+<label for="draft">Synthetic draft</label><textarea id="draft" maxlength="4096" rows="8" disabled></textarea>
+<button type="button" id="save" disabled>Save draft</button><button type="button" id="clear" disabled>Clear draft</button>
+<p id="status" role="status">Loading your plugin draft…</p></main><script src="theme.js"></script><script src="page.js"></script></body></html>

examples/plugins/session-scratchpad/page.js

@@ -0,0 +1,25 @@
+"use strict";
+/* global document, window */
+const draft = document.getElementById("draft");
+const status = document.getElementById("status");
+let busy = false;
+async function save(clear) {
+  if (busy) return;
+  busy = true;
+  try {
+    const text = clear ? "" : draft.value;
+    await window.netcattyView.setState({ version: 1, text });
+    if (clear) draft.value = "";
+    status.textContent = clear ? "Draft cleared." : "Draft saved in this plugin only.";
+  } catch { status.textContent = "Could not save this draft."; }
+  finally { busy = false; }
+}
+document.getElementById("save").addEventListener("click", () => { void save(false); });
+document.getElementById("clear").addEventListener("click", () => { void save(true); });
+window.netcattyView.getState().then((state) => {
+  if (state?.version === 1 && typeof state.text === "string" && state.text.length <= 4096) draft.value = state.text;
+  status.textContent = "Ready. Use synthetic text for this example.";
+  draft.disabled = false;
+  document.getElementById("save").disabled = false;
+  document.getElementById("clear").disabled = false;
+}).catch(() => { status.textContent = "Could not load this plugin draft."; });

examples/plugins/session-scratchpad/theme.js

@@ -0,0 +1,24 @@
+"use strict";
+/* global document, window */
+// This page owns its DOM. Only the host's public semantic colors are copied.
+(() => {
+  const names = ["--background", "--foreground", "--muted", "--muted-foreground", "--border", "--primary", "--primary-foreground"];
+  let subscription;
+  const subscribe = () => {
+    if (subscription) return;
+    subscription = window.netcattyView.onDidChangeEnvironment((environment) => {
+      const root = document.documentElement;
+      root.style.colorScheme = environment.theme === "system" ? "light dark" : environment.theme;
+      root.dataset.reducedMotion = String(Boolean(environment.reducedMotion));
+      root.dataset.highContrast = String(Boolean(environment.highContrast));
+      for (const name of names) {
+        const value = environment.themeTokens?.[name];
+        if (typeof value === "string" && value.length <= 96) root.style.setProperty(name, value);
+        else root.style.removeProperty(name);
+      }
+    });
+  };
+  subscribe();
+  window.addEventListener("pagehide", () => { subscription?.dispose(); subscription = undefined; });
+  window.addEventListener("pageshow", subscribe);
+})();

examples/plugins/starter-netcatty/README.md

@@ -35,3 +35,5 @@ images does not activate the plugin or request permissions. This example now
 requires API `>=0.1.0-internal.1 <0.2.0` and `metadata.brand-icon`.
 Older Starter 0.1.1 packages remain compatible with the new host.
 See [brand icon author instructions](../../../docs/plugin-platform/plugin-icons.md).
+
+The page subscribes to `window.netcattyView.onDidChangeEnvironment()` in `theme.js`. It follows the seven public HSL theme variables, including accent changes, without reading host settings or DOM. The subscription is disposed on page hide.

examples/plugins/starter-netcatty/netcatty.plugin.json

@@ -7,7 +7,7 @@
     "zh-CN": "插件入门"
   },
   "description": "First-party settings and command example. No terminal, network, filesystem or secret access.",
-  "version": "0.1.2",
+  "version": "0.1.3",
   "publisher": "netcatty",
   "license": "GPL-3.0-or-later",
   "engines": {

examples/plugins/starter-netcatty/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@netcatty/example-starter-plugin",
-  "version": "0.1.2",
+  "version": "0.1.3",
   "private": true,
   "type": "module",
   "scripts": {

examples/plugins/starter-netcatty/panel.css

@@ -1 +1,20 @@
-:root { color-scheme: light dark; font: 15px/1.6 system-ui, sans-serif; } body { margin: 0; } main { padding: 32px; max-width: 640px; margin: auto; } .eyebrow { font-size: 11px; letter-spacing: .12em; opacity: .65; } h1 { font-size: 24px; } #description { opacity: .75; } button { font: inherit; color: inherit; background: transparent; border: 1px solid currentColor; border-radius: 8px; padding: 8px 16px; cursor: pointer; } button:disabled { opacity: .5; } #result { white-space: pre-wrap; overflow-wrap: anywhere; padding: 16px; border-radius: 8px; background: light-dark(#f3f4f6, #252525); min-height: 24px; }
+:root { color-scheme: light dark; font: 14px/1.6 system-ui, sans-serif; }
+* { box-sizing: border-box; }
+body { margin: 0; padding: 24px; background: hsl(var(--background, 0 0% 100%)); color: hsl(var(--foreground, 222 47% 12%)); }
+main { min-width: 0; overflow-wrap: anywhere; max-width: 720px; margin: auto; }
+h1 { margin: 0 0 8px; font-size: 22px; line-height: 1.3; letter-spacing: -.02em; }
+p { color: hsl(var(--muted-foreground, 215 20% 35%)); }
+label { display: block; font-weight: 600; }
+textarea { display: block; width: 100%; min-width: 0; resize: vertical; min-height: 140px; margin: 10px 0 16px; padding: 12px; border: 1px solid hsl(var(--border, 215 20% 75%)); border-radius: 10px; background: hsl(var(--muted, 210 20% 96%)); color: inherit; font: inherit; }
+button { padding: 8px 14px; margin: 0 8px 8px 0; border: 1px solid hsl(var(--border, 215 20% 75%)); border-radius: 8px; background: hsl(var(--background, 0 0% 100%)); color: inherit; font: inherit; font-weight: 500; cursor: pointer; }
+#save, #greet { border-color: transparent; background: hsl(var(--primary, 221 83% 45%)); color: hsl(var(--primary-foreground, 0 0% 100%)); }
+button:hover:not(:disabled) { filter: brightness(.96); }
+button:disabled { opacity: .5; cursor: default; }
+button:focus-visible, textarea:focus-visible { outline: 2px solid hsl(var(--primary, 221 83% 45%)); outline-offset: 3px; }
+#status { min-height: 1.5em; font-size: 12px; }
+#result { white-space: pre-wrap; overflow-wrap: anywhere; padding: 16px; border-radius: 10px; background: hsl(var(--muted, 210 20% 96%)); min-height: 48px; }
+.eyebrow { color: hsl(var(--muted-foreground, 215 20% 35%)); font-size: 11px; letter-spacing: .1em; }
+@media (max-width: 360px) { body { padding: 16px; } }
+@media (forced-colors: active) { button, textarea { border: 1px solid ButtonText; } }
+
+@media (prefers-color-scheme: dark) { :root { --background: 221 39% 11%; --foreground: 210 20% 98%; --muted: 219 27% 21%; --muted-foreground: 220 13% 91%; --border: 218 11% 65%; --primary: 213 97% 87%; --primary-foreground: 221 39% 11%; } }

examples/plugins/starter-netcatty/panel.html

@@ -1,3 +1,3 @@
 <!doctype html>
 <html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><link rel="stylesheet" href="panel.css"><title>Plugin Starter</title></head>
-<body><main><p class="eyebrow">NETCATTY · PLUGIN STARTER</p><h1 id="title">Your first plugin</h1><p id="description">Read your Greeting preference and show it here. No hosts, terminals or secrets are accessed.</p><button id="greet" type="button">Show greeting</button><p id="result" role="status" aria-live="polite"></p></main><script src="panel.js"></script></body></html>
+<body><main><p class="eyebrow">NETCATTY · PLUGIN STARTER</p><h1 id="title">Your first plugin</h1><p id="description">Read your Greeting preference and show it here. No hosts, terminals or secrets are accessed.</p><button id="greet" type="button">Show greeting</button><p id="result" role="status" aria-live="polite"></p></main><script src="theme.js"></script><script src="panel.js"></script></body></html>

examples/plugins/starter-netcatty/theme.js

@@ -0,0 +1,24 @@
+"use strict";
+/* global document, window */
+// This page owns its DOM. Only the host's public semantic colors are copied.
+(() => {
+  const names = ["--background", "--foreground", "--muted", "--muted-foreground", "--border", "--primary", "--primary-foreground"];
+  let subscription;
+  const subscribe = () => {
+    if (subscription) return;
+    subscription = window.netcattyView.onDidChangeEnvironment((environment) => {
+      const root = document.documentElement;
+      root.style.colorScheme = environment.theme === "system" ? "light dark" : environment.theme;
+      root.dataset.reducedMotion = String(Boolean(environment.reducedMotion));
+      root.dataset.highContrast = String(Boolean(environment.highContrast));
+      for (const name of names) {
+        const value = environment.themeTokens?.[name];
+        if (typeof value === "string" && value.length <= 96) root.style.setProperty(name, value);
+        else root.style.removeProperty(name);
+      }
+    });
+  };
+  subscribe();
+  window.addEventListener("pagehide", () => { subscription?.dispose(); subscription = undefined; });
+  window.addEventListener("pageshow", subscribe);
+})();

examples/plugins/vault-scratchpad/README.md

@@ -0,0 +1,29 @@
+# Vault Scratchpad
+
+Browser-only example of an actual Vault extension page. It needs only `views`
+and the required `views.vault-pages` feature. No host/session/Vault data,
+clipboard, network, filesystem, credentials or shell permission is requested.
+Text explicitly typed here is stored in this plugin's own bounded view state;
+it is not a Netcatty Note and is not automatically cloud-synced.
+
+```sh
+node packages/plugin-cli/dist/cli.js pack examples/plugins/vault-scratchpad --out /tmp/vault-scratchpad.ncpkg
+```
+
+Import disabled through normal Settings, inspect and enable it. Under Vault's
+**Extensions** group choose **Scratchpad**. The sandbox must fill Vault's main
+content area, retaining the built-in sidebar and top tabs. Opening its detail
+entry must navigate to this same Vault page, without creating a top plugin tab.
+
+For native QA, a separate explicit approval for this fixture's own `views`
+permission is required; earlier fixtures' grants do not cover this ID. With
+synthetic text, save, return to Hosts and reopen; verify the draft. Clear and
+reopen to verify deletion. Cancel the first permission prompt to verify that no
+page attaches. Switch away during opening, then disable/revoke and verify the
+page/entry disappear. Closing or withdrawing a page returns to Hosts. A host
+modal or overlapping menu must hide the native view while it is present.
+
+This source example is not independent/native acceptance evidence. Parent QA
+records the precise tested commit and package hash separately.
+
+The page subscribes to `window.netcattyView.onDidChangeEnvironment()` in `theme.js`. It follows the seven public HSL theme variables, including accent changes, without reading host settings or DOM. The subscription is disposed on page hide.

examples/plugins/vault-scratchpad/browser.js

@@ -0,0 +1 @@
+export default { activate() {} };

examples/plugins/vault-scratchpad/netcatty.plugin.json

@@ -0,0 +1,23 @@
+{
+  "manifestVersion": 1,
+  "id": "com.netcatty.vault-scratchpad",
+  "name": "vault-scratchpad",
+  "displayName": { "en": "Vault Scratchpad", "zh-CN": "Vault 草稿板" },
+  "version": "0.1.1",
+  "publisher": "netcatty",
+  "license": "GPL-3.0-or-later",
+  "engines": { "netcatty": ">=0.0.0", "api": ">=0.1.0-internal.1 <0.2.0" },
+  "features": { "required": ["views.vault-pages"] },
+  "main": { "browser": "browser.js" },
+  "activationEvents": ["onView:com.netcatty.vault-scratchpad.page"],
+  "permissions": { "required": ["views"] },
+  "contributes": {
+    "views": [{
+      "id": "com.netcatty.vault-scratchpad.page",
+      "title": { "en": "Scratchpad", "zh-CN": "草稿板" },
+      "location": "vault-page",
+      "entry": "page.html",
+      "order": 10
+    }]
+  }
+}

examples/plugins/vault-scratchpad/page.css

@@ -0,0 +1,20 @@
+:root { color-scheme: light dark; font: 14px/1.6 system-ui, sans-serif; }
+* { box-sizing: border-box; }
+body { margin: 0; padding: 24px; background: hsl(var(--background, 0 0% 100%)); color: hsl(var(--foreground, 222 47% 12%)); }
+main { min-width: 0; overflow-wrap: anywhere; max-width: 720px; margin: auto; }
+h1 { margin: 0 0 8px; font-size: 22px; line-height: 1.3; letter-spacing: -.02em; }
+p { color: hsl(var(--muted-foreground, 215 20% 35%)); }
+label { display: block; font-weight: 600; }
+textarea { display: block; width: 100%; min-width: 0; resize: vertical; min-height: 140px; margin: 10px 0 16px; padding: 12px; border: 1px solid hsl(var(--border, 215 20% 75%)); border-radius: 10px; background: hsl(var(--muted, 210 20% 96%)); color: inherit; font: inherit; }
+button { padding: 8px 14px; margin: 0 8px 8px 0; border: 1px solid hsl(var(--border, 215 20% 75%)); border-radius: 8px; background: hsl(var(--background, 0 0% 100%)); color: inherit; font: inherit; font-weight: 500; cursor: pointer; }
+#save, #greet { border-color: transparent; background: hsl(var(--primary, 221 83% 45%)); color: hsl(var(--primary-foreground, 0 0% 100%)); }
+button:hover:not(:disabled) { filter: brightness(.96); }
+button:disabled { opacity: .5; cursor: default; }
+button:focus-visible, textarea:focus-visible { outline: 2px solid hsl(var(--primary, 221 83% 45%)); outline-offset: 3px; }
+#status { min-height: 1.5em; font-size: 12px; }
+#result { white-space: pre-wrap; overflow-wrap: anywhere; padding: 16px; border-radius: 10px; background: hsl(var(--muted, 210 20% 96%)); min-height: 48px; }
+.eyebrow { color: hsl(var(--muted-foreground, 215 20% 35%)); font-size: 11px; letter-spacing: .1em; }
+@media (max-width: 360px) { body { padding: 16px; } }
+@media (forced-colors: active) { button, textarea { border: 1px solid ButtonText; } }
+
+@media (prefers-color-scheme: dark) { :root { --background: 221 39% 11%; --foreground: 210 20% 98%; --muted: 219 27% 21%; --muted-foreground: 220 13% 91%; --border: 218 11% 65%; --primary: 213 97% 87%; --primary-foreground: 221 39% 11%; } }

examples/plugins/vault-scratchpad/page.html

@@ -0,0 +1,7 @@
+<!doctype html>
+<html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
+<title>Vault Scratchpad</title><link rel="stylesheet" href="page.css"></head>
+<body><main><h1>Scratchpad</h1><p>This page stores only text you type here, in this plugin's own view state. It cannot read Vault hosts, notes, credentials, sessions or the clipboard.</p>
+<label for="draft">Synthetic draft</label><textarea id="draft" maxlength="4096" rows="8" disabled></textarea>
+<button type="button" id="save" disabled>Save draft</button><button type="button" id="clear" disabled>Clear draft</button>
+<p id="status" role="status">Loading your plugin draft…</p></main><script src="theme.js"></script><script src="page.js"></script></body></html>

examples/plugins/vault-scratchpad/page.js

@@ -0,0 +1,25 @@
+"use strict";
+/* global document, window */
+const draft = document.getElementById("draft");
+const status = document.getElementById("status");
+let busy = false;
+async function save(clear) {
+  if (busy) return;
+  busy = true;
+  try {
+    const text = clear ? "" : draft.value;
+    await window.netcattyView.setState({ version: 1, text });
+    if (clear) draft.value = "";
+    status.textContent = clear ? "Draft cleared." : "Draft saved in this plugin only.";
+  } catch { status.textContent = "Could not save this draft."; }
+  finally { busy = false; }
+}
+document.getElementById("save").addEventListener("click", () => { void save(false); });
+document.getElementById("clear").addEventListener("click", () => { void save(true); });
+window.netcattyView.getState().then((state) => {
+  if (state?.version === 1 && typeof state.text === "string" && state.text.length <= 4096) draft.value = state.text;
+  status.textContent = "Ready. Use synthetic text for this example.";
+  draft.disabled = false;
+  document.getElementById("save").disabled = false;
+  document.getElementById("clear").disabled = false;
+}).catch(() => { status.textContent = "Could not load this plugin draft."; });