feat(plugins): bind static reads to versioned snapshot sidecar

# Conflicts:
#	application/i18n/locales/en/core.ts
#	application/i18n/locales/es/core.ts
#	application/i18n/locales/ru/core.ts
#	application/i18n/locales/zh-CN/core.ts
#	application/i18n/locales/zh-TW/core.ts

application/i18n/locales/en/core.ts

@@ -1255,8 +1255,14 @@ Highlight the focused split pane:
   "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.",
   "settings.plugins.market.results": "{count} plugins",
   "settings.plugins.manager.lastError": "Last recorded error",
+  "settings.plugins.market.offline": "Registry unavailable. Showing the last valid catalog or bundled examples. Installation is unavailable until refresh succeeds.",
   "settings.plugins.manager.details": "View details",
   "settings.plugins.manager.noDescription": "No description provided.",
+  "settings.plugins.status": "Notices: {count}",
+  "settings.plugins.info": "Plugin information",
+  "settings.plugins.manager.noVaultShort": "Secret storage unavailable",
+  "settings.plugins.market.offlineShort": "Offline catalog · installation unavailable",
+  "settings.plugins.market.readmeInfo": "About this README",
   "settings.plugins.market.installed": "Installed",
   "settings.plugins.market.sourceBadge": "Source example",
   "settings.plugins.market.title": "Marketplace",

application/i18n/locales/es/core.ts

@@ -1255,8 +1255,14 @@ Resalta el panel dividido enfocado:
   "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.",
   "settings.plugins.market.results": "{count} plugins",
   "settings.plugins.manager.lastError": "Último error registrado",
+  "settings.plugins.market.offline": "El registro no está disponible. Se muestra el último catálogo válido o los ejemplos incluidos. La instalación requiere una actualización correcta.",
   "settings.plugins.manager.details": "Ver detalles",
   "settings.plugins.manager.noDescription": "No se proporcionó una descripción.",
+  "settings.plugins.status": "{count} avisos",
+  "settings.plugins.info": "Información de plugins",
+  "settings.plugins.manager.noVaultShort": "Almacenamiento de secretos no disponible",
+  "settings.plugins.market.offlineShort": "Catálogo sin conexión · instalación no disponible",
+  "settings.plugins.market.readmeInfo": "Acerca de este README",
   "settings.plugins.market.installed": "Instalado",
   "settings.plugins.market.sourceBadge": "Ejemplo de código",
   "settings.plugins.market.title": "Catálogo",

application/i18n/locales/ru/core.ts

@@ -1150,8 +1150,14 @@ export const ruCoreMessages: Messages = {
   "settings.plugins.manager.data": "Данные KV остаются на устройстве. Синхронизируются только явно отмеченные несекретные настройки в зашифрованных данных. Пакеты и разрешения не синхронизируются.",
   "settings.plugins.market.results": "Плагинов: {count}",
   "settings.plugins.manager.lastError": "Последняя записанная ошибка",
+  "settings.plugins.market.offline": "Реестр недоступен. Показан последний корректный каталог или встроенные примеры. Для установки необходимо успешно обновить каталог.",
   "settings.plugins.manager.details": "Подробнее",
   "settings.plugins.manager.noDescription": "Описание не предоставлено.",
+  "settings.plugins.status": "Уведомления: {count}",
+  "settings.plugins.info": "Информация о плагинах",
+  "settings.plugins.manager.noVaultShort": "Хранилище секретов недоступно",
+  "settings.plugins.market.offlineShort": "Каталог офлайн · установка недоступна",
+  "settings.plugins.market.readmeInfo": "Об этом README",
   "settings.plugins.market.installed": "Установлен",
   "settings.plugins.market.sourceBadge": "Пример исходного кода",
   "settings.plugins.market.title": "Каталог",

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

@@ -1170,8 +1170,14 @@ Vaults 标签保持扁平，不使用这块背景。
   "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。",
   "settings.plugins.market.results": "{count} 个插件",
   "settings.plugins.manager.lastError": "上次记录的错误",
+  "settings.plugins.market.offline": "官方目录暂时不可用，正在显示上次有效目录或内置示例。刷新成功前不能从市场安装。",
   "settings.plugins.manager.details": "查看详情",
   "settings.plugins.manager.noDescription": "作者暂未提供功能简介。",
+  "settings.plugins.status": "{count} 项提醒",
+  "settings.plugins.info": "插件说明",
+  "settings.plugins.manager.noVaultShort": "凭据存储不可用",
+  "settings.plugins.market.offlineShort": "目录离线 · 暂不可安装",
+  "settings.plugins.market.readmeInfo": "README 来源说明",
   "settings.plugins.market.installed": "已安装",
   "settings.plugins.market.sourceBadge": "源码示例",
   "settings.plugins.market.title": "插件市场",

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

@@ -1179,8 +1179,14 @@ Vaults 分頁維持扁平，不使用這塊背景。
   'settings.plugins.loading': '正在載入外掛程式設定…',
   "settings.plugins.market.results": "{count} 個插件",
   "settings.plugins.manager.lastError": "上次記錄的錯誤",
+  "settings.plugins.market.offline": "官方目錄暫時無法使用，正在顯示上次有效目錄或內建範例。重新整理成功前無法從市場安裝。",
   "settings.plugins.manager.details": "查看詳情",
   "settings.plugins.manager.noDescription": "作者尚未提供功能簡介。",
+  "settings.plugins.status": "{count} 項提醒",
+  "settings.plugins.info": "外掛說明",
+  "settings.plugins.manager.noVaultShort": "憑據儲存無法使用",
+  "settings.plugins.market.offlineShort": "目錄離線 · 暫時無法安裝",
+  "settings.plugins.market.readmeInfo": "README 來源說明",
   "settings.plugins.market.installed": "已安裝",
   "settings.plugins.market.sourceBadge": "原始碼範例",
   "settings.plugins.market.title": "插件市場",

application/state/usePluginCatalog.test.ts

@@ -16,7 +16,7 @@ test('README failures clear on retry/switch and stale requests cannot replace th
   const calls: Array<{ id: string; request: ReturnType<typeof deferred<string>> }> = [];
   Object.defineProperty(globalThis, 'window', { configurable: true, value: {
     netcatty: {
-      listPluginCatalog: async () => [],
+      listPluginCatalog: async () => ({ entries: [], source: "builtin", error: null }),
       getPluginCatalogReadme: (id: string) => { const request = deferred<string>(); calls.push({ id, request }); return request.promise; },
     },
   } });
@@ -50,3 +50,35 @@ test('README failures clear on retry/switch and stale requests cannot replace th
   await act(async () => calls[4].request.resolve('late content'));
   assert.equal(renders, unmountedRenders);
 });
+
+test('offline snapshot stays browsable, retry clears warning, and operations bind the selected token', async (context) => {
+  const original = Object.getOwnPropertyDescriptor(globalThis, 'window');
+  const entry = { id: 'com.test.registry', selectionToken: 'first' } as NetcattyPluginCatalogEntry;
+  let offline = true;
+  const reads: unknown[][] = []; const installs: unknown[][] = [];
+  Object.defineProperty(globalThis, 'window', { configurable: true, value: {
+    dispatchEvent() {}, netcatty: {
+      listPluginCatalog: async () => ({ entries: [{ ...entry, selectionToken: offline ? 'first' : 'second' }], source: offline ? 'cached' : 'registry', error: offline ? 'offline' : null }),
+      getPluginCatalogReadme: async (...args: unknown[]) => { reads.push(args); return '# Pinned'; },
+      installCatalogPlugin: async (...args: unknown[]) => { installs.push(args); },
+    },
+  } });
+  (globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+  context.after(() => {
+    if (original) Object.defineProperty(globalThis, 'window', original); else Reflect.deleteProperty(globalThis, 'window');
+    Reflect.deleteProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT');
+  });
+  let state!: ReturnType<typeof usePluginCatalog>;
+  function Probe() { state = usePluginCatalog(entry.id); return null; }
+  let renderer!: ReactTestRenderer;
+  await act(async () => { renderer = create(React.createElement(Probe)); });
+  assert.equal(state.entries.length, 1); assert.equal(state.listStatus, 'ready'); assert.equal(state.listError, 'offline');
+  assert.equal(state.source, 'cached');
+  offline = false;
+  await act(async () => state.retryList());
+  assert.equal(state.listError, null); assert.equal(state.source, 'registry');
+  assert.deepEqual(reads.at(-1), [entry.id, 'second']);
+  await act(async () => state.install(entry.id));
+  assert.deepEqual(installs, [[entry.id, 'second']]);
+  await act(async () => renderer.unmount());
+});

application/state/usePluginCatalog.ts

@@ -1,10 +1,11 @@
 import { useEffect, useRef, useState } from 'react';
 import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
 
-type ReadmeState = { id: string; attempt: number; status: 'loading' | 'ready' | 'error'; text: string; error: string | null };
+type ReadmeState = { id: string; token?: string; attempt: number; status: 'loading' | 'ready' | 'error'; text: string; error: string | null };
 export function usePluginCatalog(selectedId: string | null) {
   const [entries, setEntries] = useState<NetcattyPluginCatalogEntry[]>([]);
   const [listStatus, setListStatus] = useState<'loading' | 'ready' | 'error'>('loading');
+  const [source, setSource] = useState<NetcattyPluginCatalogSnapshot['source']>('builtin');
   const [listError, setListError] = useState<string | null>(null);
   const [listAttempt, setListAttempt] = useState(0);
   const [readmeState, setReadmeState] = useState<ReadmeState | null>(null);
@@ -22,29 +23,30 @@ export function usePluginCatalog(selectedId: string | null) {
         const bridge = netcattyBridge.get();
         if (!bridge?.listPluginCatalog) throw new Error('Catalog browsing unavailable');
         const list = await bridge.listPluginCatalog();
-        if (active) { setEntries(list); setListStatus('ready'); }
+        if (active) { setEntries(list.entries); setSource(list.source); setListError(list.error); setListStatus('ready'); }
       } catch (cause) { if (active) { setListStatus('error'); setListError(String(cause)); } }
     })();
     return () => { active = false; };
   }, [listAttempt]);
+  const selectionToken = entries.find((entry) => entry.id === selectedId)?.selectionToken;
   useEffect(() => {
     if (!selectedId) return;
     let active = true;
-    const base = { id: selectedId, attempt: readmeAttempt, text: '', error: null };
+    const base = { id: selectedId, token: selectionToken, attempt: readmeAttempt, text: '', error: null };
     setReadmeState({ ...base, status: 'loading' });
     void (async () => {
       try {
         const bridge = netcattyBridge.get();
         if (!bridge?.getPluginCatalogReadme) throw new Error('README retrieval unavailable');
-        const text = await bridge.getPluginCatalogReadme(selectedId);
+        const text = await bridge.getPluginCatalogReadme(selectedId, selectionToken);
         if (active) setReadmeState({ ...base, status: 'ready', text });
       } catch (cause) { if (active) setReadmeState({ ...base, status: 'error', error: String(cause) }); }
     })();
     return () => { active = false; };
-  }, [selectedId, readmeAttempt]);
-  const currentReadme = readmeState?.id === selectedId && readmeState.attempt === readmeAttempt ? readmeState : null;
+  }, [selectedId, selectionToken, readmeAttempt]);
+  const currentReadme = readmeState?.id === selectedId && readmeState.token === selectionToken && readmeState.attempt === readmeAttempt ? readmeState : null;
   return {
-    entries, listStatus, listError,
+    entries, listStatus, listError, source,
     readme: currentReadme?.status === 'ready' ? currentReadme.text : null,
     readmeStatus: currentReadme?.status ?? (selectedId ? 'loading' : 'idle'),
     readmeError: currentReadme?.error ?? null,
@@ -59,7 +61,7 @@ export function usePluginCatalog(selectedId: string | null) {
       try {
         const bridge = netcattyBridge.require();
         if (!bridge.installCatalogPlugin) throw new Error('Catalog installation unavailable');
-        await bridge.installCatalogPlugin(id);
+        await bridge.installCatalogPlugin(id, entries.find((entry) => entry.id === id)?.selectionToken);
         window.dispatchEvent(new Event('netcatty:plugin-packages-changed'));
       } catch (cause) { if (mounted.current) setInstallError({ id, message: String(cause) }); }
       finally { installing.current = false; if (mounted.current) setBusy(false); }

components/settings/tabs/PluginInfo.interaction.test.tsx

@@ -0,0 +1,114 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { JSDOM } from 'jsdom';
+
+test('information previews on hover/focus, pins on click and Escape returns focus without closing the manager', 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', 'Node', 'NodeFilter', 'MutationObserver', 'CustomEvent', 'Event', 'KeyboardEvent', 'MouseEvent']) {
+    install(key, key === 'window' ? dom.window : dom.window[key as keyof typeof dom.window]);
+  }
+  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);
+  const { default: React, act, useState } = await import('react');
+  const { createRoot } = await import('react-dom/client');
+  const { PluginInfo } = await import('./PluginInfo');
+  const { PluginManagementDialog } = await import('./PluginManagementDialog');
+  const { I18nProvider } = await import('../../../application/i18n/I18nProvider');
+  const root = createRoot(document.getElementById('root')!);
+  const settle = (ms = 60) => new Promise((resolve) => setTimeout(resolve, ms));
+  try {
+    await act(async () => root.render(<I18nProvider locale="en"><PluginManagementDialog><PluginInfo label="Plugin help">Packages remain disabled until reviewed.</PluginInfo><button data-other>Other control</button></PluginManagementDialog></I18nProvider>));
+    await act(async () => { document.querySelector<HTMLButtonElement>('button')!.click(); await settle(); });
+    const trigger = document.querySelector<HTMLButtonElement>('button[aria-label="Plugin help"]')!;
+    const other = document.querySelector<HTMLButtonElement>('[data-other]')!;
+    assert.ok(trigger); assert.equal(trigger.getAttribute('title'), null, 'not a native title-only hint');
+    await act(async () => { other.focus(); await settle(); });
+    const hover = new MouseEvent('pointermove', { bubbles: true });
+    Object.defineProperty(hover, 'pointerType', { value: 'mouse' });
+    await act(async () => { trigger.dispatchEvent(hover); await settle(260); });
+    assert.match(document.querySelector('[role="tooltip"]')?.textContent ?? '', /Packages remain disabled/);
+    await act(async () => { trigger.focus(); await settle(); });
+    assert.ok(document.querySelector('[role="tooltip"]'));
+    await act(async () => { trigger.click(); await settle(); });
+    const pinned = document.querySelector<HTMLElement>('[role="dialog"][aria-label="Plugin help"]');
+    assert.ok(pinned, 'click exposes a persistent readable popover');
+    assert.equal(document.querySelector('[role="tooltip"]'), null);
+    await act(async () => { pinned.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true, cancelable: true })); await settle(); });
+    assert.equal(document.querySelector('[role="dialog"][aria-label="Plugin help"]'), null);
+    assert.equal(document.querySelectorAll('[role="dialog"]').length, 1, 'Escape closes only the information layer');
+    assert.equal(document.activeElement, trigger);
+    assert.equal(Boolean(document.querySelector('[role="tooltip"]')), false, 'Escape does not immediately reopen the focus preview');
+    await act(async () => { other.focus(); trigger.focus(); await settle(); });
+    assert.ok(document.querySelector('[role="tooltip"]'), 'a subsequent deliberate focus still previews help');
+
+    const { PluginMarketplaceContent } = await import('./PluginMarketplace');
+    const entry = { id: 'com.example.guide', name: 'Guide', author: 'Example', version: '1.0.0', license: 'MIT', repository: 'example/plugin', commit: 'a'.repeat(40), description: 'Synthetic metadata',
+      manifest: { id: 'com.example.guide', name: 'Guide', publisher: 'Example', main: { browser: 'index.js' }, engines: { netcatty: '*', api: '0.1.0-internal' } },
+    } as NetcattyPluginCatalogEntry;
+    const catalog = { entries: [entry], source: 'registry', listStatus: 'ready', listError: null, readme: '# Guide', readmeStatus: 'ready', readmeError: null, error: null, busy: false, retryList() {}, retryReadme() {}, async install() {} } as ReturnType<typeof import('../../../application/state/usePluginCatalog').usePluginCatalog>;
+    function Browser() {
+      const [selected, setSelected] = useState<string | null>(null);
+      const [toolbar, setToolbar] = useState<HTMLDivElement | null>(null);
+      return <I18nProvider locale="en"><div data-toolbar ref={setToolbar} /><div data-settings-scroll-pane><PluginMarketplaceContent catalog={catalog} installed={[]} selected={selected} onSelect={setSelected} toolbarContainer={toolbar} /></div></I18nProvider>;
+    }
+    await act(async () => { root.render(<Browser />); await settle(); });
+    const pane = document.querySelector<HTMLElement>('[data-settings-scroll-pane]')!;
+    assert.match(document.querySelector('[data-toolbar]')?.textContent ?? '', /Refresh/);
+    pane.scrollTop = 450;
+    await act(async () => { document.querySelector<HTMLButtonElement>('[data-plugin-id]')!.click(); await settle(); });
+    assert.equal(document.querySelector('.plugin-marketplace-catalog'), null, 'detail replaces the candidate list');
+    assert.doesNotMatch(document.querySelector('[data-toolbar]')?.textContent ?? '', /Refresh/, 'list refresh stays out of detail');
+    assert.equal(pane.scrollTop, 0);
+    assert.equal(document.activeElement?.tagName, 'H4');
+    assert.equal(document.activeElement?.textContent, 'Guide');
+    const back = Array.from(document.querySelectorAll('button')).find((button) => button.textContent?.includes('All plugins'))!;
+    await act(async () => { back.click(); await settle(); });
+    assert.equal(pane.scrollTop, 450);
+    assert.equal(document.activeElement?.getAttribute('data-plugin-id'), entry.id);
+    assert.match(document.querySelector('[data-toolbar]')?.textContent ?? '', /Refresh/);
+
+    const { PluginStatus } = await import('./PluginStatus');
+    function StatusHarness() {
+      const [offline, setOffline] = useState(true);
+      const [noVault, setNoVault] = useState(true);
+      return <I18nProvider locale="en"><PluginStatus noVault={noVault} offlineError={offline ? 'Network unavailable' : null} retry={() => setOffline(false)} /><button onClick={() => setNoVault(false)}>Restore vault</button></I18nProvider>;
+    }
+    await act(async () => { root.render(<StatusHarness />); await settle(); });
+    const status = document.querySelector<HTMLButtonElement>('button[aria-label$="Notices: 2"]')!;
+    await act(async () => { status.focus(); await settle(); });
+    assert.match(document.querySelector('[role="tooltip"]')?.textContent ?? '', /Network unavailable/);
+    assert.equal(document.querySelector('[role="tooltip"] button'), null, 'hover preview never contains an interactive Retry');
+    await act(async () => { status.click(); await settle(); });
+    const retry = document.querySelector<HTMLButtonElement>('[role="dialog"] button')!;
+    assert.equal(retry.textContent, 'Retry');
+    assert.equal(status.textContent, '2', 'only the number badge is visible, not a second text label');
+    assert.equal(document.querySelectorAll('button[aria-label*="Notices:"]').length, 1);
+    assert.match(document.querySelector('[role="dialog"]')?.textContent ?? '', /Updates are manual/);
+    assert.ok(document.querySelector('[role="dialog"] hr'));
+    await act(async () => { retry.click(); await settle(); });
+    assert.ok(document.querySelector('button[aria-label$="Notices: 1"]'));
+    assert.doesNotMatch(document.querySelector('[role="dialog"]')?.textContent ?? '', /Network unavailable/);
+    await act(async () => { document.querySelector('[role="dialog"]')!.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true, cancelable: true })); await settle(); });
+    assert.match(document.activeElement?.getAttribute('aria-label') ?? '', /Notices: 1$/);
+    await act(async () => { Array.from(document.querySelectorAll('button')).find((button) => button.textContent === 'Restore vault')!.click(); await settle(); });
+    const healthy = document.querySelector<HTMLButtonElement>('button[aria-label="Plugin information"]')!;
+    assert.ok(healthy, 'one information control remains when healthy');
+    assert.equal(healthy.querySelector('span[aria-hidden="true"]'), null, 'healthy control has no count badge');
+    await act(async () => { healthy.click(); await settle(); });
+    assert.match(document.querySelector('[role="dialog"]')?.textContent ?? '', /Updates are manual/);
+    await act(async () => { document.querySelector('[role="dialog"]')!.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true, cancelable: true })); await settle(); });
+  } finally {
+    await act(async () => root.unmount());
+    dom.window.close();
+    for (const [key, descriptor] of previous) {
+      if (descriptor) Object.defineProperty(globalThis, key, descriptor); else Reflect.deleteProperty(globalThis, key);
+    }
+  }
+});

components/settings/tabs/PluginInfo.tsx

@@ -0,0 +1,25 @@
+import React, { useRef, useState } from 'react';
+import { Info } from 'lucide-react';
+import { Button } from '../../ui/button';
+import { Popover, PopoverContent, PopoverTrigger } from '../../ui/popover';
+import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from '../../ui/tooltip';
+
+/** Hover/focus previews explanatory text; click pins it in the existing accessible popover. */
+export function PluginInfo({ label, children, badgeCount, previewContent }: { label: string; children: React.ReactNode; badgeCount?: number; previewContent?: React.ReactNode }) {
+  const [pinned, setPinned] = useState(false);
+  const [preview, setPreview] = useState(false);
+  const suppressFocusPreview = useRef(false);
+  return <Popover open={pinned} onOpenChange={(open) => { setPinned(open); setPreview(false); }}>
+    <TooltipProvider delayDuration={200}>
+      <Tooltip open={!pinned && preview} onOpenChange={(open) => { if (!open || !suppressFocusPreview.current) setPreview(open); }}>
+        <TooltipTrigger asChild><PopoverTrigger asChild>
+          <Button type="button" variant="ghost" size="sm" className="relative h-8 w-8 shrink-0 p-0 text-muted-foreground focus-visible:ring-2 focus-visible:ring-ring" aria-label={label} onBlur={() => { suppressFocusPreview.current = false; }} onPointerMove={() => { suppressFocusPreview.current = false; }}>
+            <Info size={15} />{Boolean(badgeCount) && <span aria-hidden="true" className="absolute right-0 top-0 flex h-3.5 min-w-3.5 items-center justify-center rounded-full bg-muted px-0.5 text-[9px] font-medium leading-none text-foreground">{badgeCount}</span>}
+          </Button>
+        </PopoverTrigger></TooltipTrigger>
+        <TooltipContent className="max-w-xs space-y-2 bg-popover p-3 text-xs leading-5 text-popover-foreground shadow-sm">{previewContent ?? children}</TooltipContent>
+      </Tooltip>
+    </TooltipProvider>
+    <PopoverContent onEscapeKeyDown={() => { suppressFocusPreview.current = true; }} aria-label={label} align="end" className="max-w-xs space-y-2 text-xs leading-5">{children}</PopoverContent>
+  </Popover>;
+}

components/settings/tabs/PluginMarketplace.interaction.test.tsx

@@ -1,5 +1,6 @@
 import assert from 'node:assert/strict';
-import test from 'node:test';
+import test, { before, after } from 'node:test';
+import { JSDOM } from 'jsdom';
 import React, { useState } from 'react';
 import { act, create, type ReactTestRenderer } from 'react-test-renderer';
 import { renderToStaticMarkup } from 'react-dom/server';
@@ -8,13 +9,26 @@ import { I18nProvider } from '../../../application/i18n/I18nProvider';
 import { PluginMarketplaceContent } from './PluginMarketplace';
 import type { usePluginCatalog } from '../../../application/state/usePluginCatalog';
 
+const infoDom = new JSDOM('<!doctype html><html><body></body></html>');
+const previousWindow = Object.getOwnPropertyDescriptor(globalThis, 'window');
+const previousDocument = Object.getOwnPropertyDescriptor(globalThis, 'document');
+before(() => {
+  Object.defineProperty(globalThis, 'window', { configurable: true, value: infoDom.window });
+  Object.defineProperty(globalThis, 'document', { configurable: true, value: infoDom.window.document });
+});
+after(() => {
+  infoDom.window.close();
+  if (previousWindow) Object.defineProperty(globalThis, 'window', previousWindow); else Reflect.deleteProperty(globalThis, 'window');
+  if (previousDocument) Object.defineProperty(globalThis, 'document', previousDocument); else Reflect.deleteProperty(globalThis, 'document');
+});
+
 const entries = ['Alpha', 'Beta'].map((name) => ({
   id: `com.example.${name.toLowerCase()}`, name, author: 'Example', version: '1.0.0', license: 'MIT',
   description: `${name} local utility`, repository: 'example/plugins', commit: 'a'.repeat(40),
   manifest: { manifestVersion: 1, id: `com.example.${name.toLowerCase()}`, name, version: '1.0.0', publisher: 'Example', engines: { netcatty: '>=1.0.0', api: '0.1.0-internal' }, main: { browser: 'index.js' }, permissions: { required: ['settings.read'] } },
 })) as NetcattyPluginCatalogEntry[];
 const catalog = {
-  entries, listStatus: 'ready', listError: null, readme: '# Author documentation', readmeStatus: 'ready', readmeError: null,
+  entries, source: 'registry', listStatus: 'ready', listError: null, readme: '# Author documentation', readmeStatus: 'ready', readmeError: null,
   error: null, busy: false, retryList() {}, retryReadme() {}, async install() {},
 } as ReturnType<typeof usePluginCatalog>;
 
@@ -39,16 +53,13 @@ test('catalog keeps search during selection/back, switches detail, and displays
     assert.equal(cards().length, 1);
     await act(async () => cards()[0].props.onClick());
     assert.equal(renderer.root.findByType('article').props['aria-label'], 'Alpha');
-    assert.equal(cards()[0].props['aria-current'], 'true');
+    assert.equal(cards().length, 0, 'detail replaces the entire grid at every width');
+    assert.equal(renderer.root.findAllByType('input').length, 0);
     const detailText = JSON.stringify(renderer.toJSON());
     assert.match(detailText, /0.9.0/);
     assert.match(detailText, /Disabled/);
     assert.match(detailText, /Incompatible with this host/);
     assert.match(detailText, /Last recorded error/);
-    assert.match(cards()[0].props.className, /bg-primary\/10/);
-    assert.match(cards()[0].props.className, /border-primary\/40/);
-    assert.doesNotMatch(cards()[0].props.className, /bg-accent|text-accent-foreground/);
-    assert.match(detailText, /1 plugins/);
     assert.equal(renderer.root.findAllByType('details').length, 0, 'permissions are not hidden in a disclosure');
     assert.equal(renderer.root.findAll((node) => node.type === 'button' && node.children.includes('Install this version (disabled)')).length, 0, 'source-only cards have no install action');
     const back = () => renderer.root.findAllByType('button').find((node) => node.children.includes('All plugins'))!;
@@ -56,15 +67,12 @@ test('catalog keeps search during selection/back, switches detail, and displays
     assert.equal(renderer.root.findAllByType('article').length, 0);
     assert.equal(input().props.value, 'Alpha');
     await act(async () => input().props.onChange({ target: { value: '' } }));
-    await act(async () => cards()[0].props.onClick());
     await act(async () => cards()[1].props.onClick());
     assert.equal(renderer.root.findByType('article').props['aria-label'], 'Beta');
-    assert.equal(cards()[1].props['aria-current'], 'true');
-    assert.equal(cards()[0].props['aria-current'], undefined);
+    assert.equal(cards().length, 0);
+    await act(async () => back().props.onClick());
     await act(async () => input().props.onChange({ target: { value: 'no match' } }));
     assert.equal(cards().length, 0);
-    assert.equal(renderer.root.findByType('article').props['aria-label'], 'Beta', 'filtering does not erase the selected detail');
-    await act(async () => back().props.onClick());
     assert.equal(input().props.value, 'no match');
     await act(async () => renderer.unmount());
   } finally {
@@ -81,29 +89,29 @@ test('README failure leaves the permissions and source visible, before the failu
   assert.match(html, /Compatibility and permissions/);
   assert.match(html, /settings.read/);
   assert.match(html, /not a grant/);
-  assert.match(html, /Build with the local CLI/);
+  assert.match(html, /Source example/);
   assert.ok(html.indexOf('settings.read') < html.indexOf('Network unavailable'));
   assert.match(html, /Retry/);
   assert.doesNotMatch(html, /<details/);
 });
 
-test('responsive layout is scoped to marketplace content width, with a narrow detail-only fallback', () => {
+test('cards use subtle shadows and details have no breakpoint-specific columns or nested scroller', () => {
   const css = readFileSync(new URL('./plugin-marketplace.css', import.meta.url), 'utf8');
-  assert.match(css, /\.plugin-marketplace \{ container-type: inline-size;/);
-  assert.match(css, /@container \(min-width: 820px\)/);
-  assert.match(css, /grid-template-columns: 248px minmax\(0, 1fr\)/);
-  assert.match(css, /plugin-marketplace-browser--selected \.plugin-marketplace-catalog \{ display: none;/);
+  assert.match(css, /box-shadow: 0 1px 4px/);
+  assert.match(css, /\.dark \.plugin-card/);
+  assert.doesNotMatch(css, /@container|248px|max-height|overflow-y/);
 });
 
-test('narrow detail starts at the top and back restores the settings scroll and card focus', async () => {
+test('full-page detail starts at the top and back restores the settings scroll and card focus', async () => {
   const previousRaf = globalThis.requestAnimationFrame;
-  globalThis.requestAnimationFrame = (callback) => { callback(0); return 0; };
+  const frames: FrameRequestCallback[] = [];
+  globalThis.requestAnimationFrame = (callback) => { frames.push(callback); return frames.length; };
   const actGlobal = globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean };
   const previousActEnvironment = actGlobal.IS_REACT_ACT_ENVIRONMENT;
   actGlobal.IS_REACT_ACT_ENVIRONMENT = true;
   const pane = { scrollTop: 450 };
   let focused = false;
-  const list = { scrollTop: 0, closest: (selector: string) => selector === '.plugin-marketplace' ? { clientWidth: 700 } : pane,
+  const list = { scrollTop: 0, closest: (selector: string) => selector === '.plugin-marketplace' ? { clientWidth: 1100 } : pane,
     querySelectorAll: () => [{ dataset: { pluginId: entries[0].id }, focus: () => { focused = true; } }] };
   let renderer!: ReactTestRenderer;
   function Harness() {
@@ -111,12 +119,14 @@ test('narrow detail starts at the top and back restores the settings scroll and
     return <I18nProvider locale="en"><PluginMarketplaceContent catalog={catalog} selected={selected} onSelect={setSelected} installed={[]} /></I18nProvider>;
   }
   try {
-    await act(async () => { renderer = create(<Harness />, { createNodeMock: (element) => element.type === 'div' ? list : { scrollTo() {}, focus() {} } }); });
+    await act(async () => { renderer = create(<Harness />, { createNodeMock: (element) => element.type === 'div' && (element.props as { className?: string }).className?.includes('plugin-marketplace-catalog') ? list : null }); });
     const card = renderer.root.findAll((node) => node.type === 'button' && node.props['data-plugin-id'] === entries[0].id)[0];
     await act(async () => card.props.onClick());
+    frames.splice(0).forEach((frame) => frame(0));
     assert.equal(pane.scrollTop, 0);
     const back = renderer.root.findAllByType('button').find((node) => node.children.includes('All plugins'))!;
     await act(async () => back.props.onClick());
+    frames.splice(0).forEach((frame) => frame(0));
     assert.equal(pane.scrollTop, 450);
     assert.equal(focused, true);
     await act(async () => renderer.unmount());
@@ -125,3 +135,30 @@ test('narrow detail starts at the top and back restores the settings scroll and
     actGlobal.IS_REACT_ACT_ENVIRONMENT = previousActEnvironment;
   }
 });
+
+test('offline catalog warning keeps details visible and disables market installation', () => {
+  const downloadable = { ...entries[0], artifact: { url: 'https://github.com/example/plugin/releases/download/v1/plugin.ncpkg', sha256: 'a'.repeat(64) } };
+  const html = renderToStaticMarkup(<I18nProvider locale="en"><PluginMarketplaceContent
+    catalog={{ ...catalog, entries: [downloadable], listError: 'Registry offline', source: 'cached' }}
+    selected={downloadable.id} onSelect={() => {}} installed={[]} /></I18nProvider>);
+  assert.match(html, /Offline catalog · installation unavailable/);
+  assert.match(html, /Compatibility and permissions/);
+  assert.match(html, /<button[^>]*disabled=""[^>]*>Install this version/);
+  assert.match(html, /Notices: 1/);
+});
+
+test('manual refresh remains available after success and is disabled while loading', () => {
+  const ready = renderToStaticMarkup(<I18nProvider locale="en"><PluginMarketplaceContent catalog={catalog} selected={null} onSelect={() => {}} installed={[]} /></I18nProvider>);
+  assert.match(ready, />Refresh<\/button>/);
+  const loading = renderToStaticMarkup(<I18nProvider locale="en"><PluginMarketplaceContent catalog={{ ...catalog, listStatus: 'loading' }} selected={null} onSelect={() => {}} installed={[]} /></I18nProvider>);
+  assert.match(loading, /<button[^>]*disabled=""[^>]*>Refresh<\/button>/);
+});
+
+test('replacing an installed plugin discloses that its running version will stop beside the install action', () => {
+  const downloadable = { ...entries[0], artifact: { url: 'https://github.com/example/plugin/releases/download/v1/plugin.ncpkg', sha256: 'a'.repeat(64) } };
+  const html = renderToStaticMarkup(<I18nProvider locale="en"><PluginMarketplaceContent
+    catalog={{ ...catalog, entries: [downloadable] }} selected={downloadable.id} onSelect={() => {}}
+    installed={[{ id: downloadable.id, activeVersion: '0.9.0', enabled: true } as NetcattyInstalledPlugin]} /></I18nProvider>);
+  assert.match(html, /<p[^>]*>This replaces and stops the installed version\./);
+  assert.ok(html.indexOf('This replaces and stops') < html.indexOf('Install this version (disabled)'));
+});

components/settings/tabs/PluginMarketplace.tsx

@@ -1,3 +1,6 @@
+import { createPortal } from 'react-dom';
+import { PluginStatus } from './PluginStatus';
+import { PluginInfo } from './PluginInfo';
 import React, { useRef, useState } from 'react';
 import { PluginBrandIcon } from '../../plugins/PluginBrandIcon';
 import { ArrowLeft } from 'lucide-react';
@@ -5,18 +8,19 @@ import { useI18n } from '../../../application/i18n/I18nProvider';
 import { usePluginCatalog } from '../../../application/state/usePluginCatalog';
 import { Input } from '../../ui/input';
 import { Button } from '../../ui/button';
-import { SettingCard } from '../settings-ui';
 import { PluginPackageDetails } from './PluginPackageManager';
 import { PluginReadme } from './PluginReadme';
 
-export function PluginMarketplace({ installed = [] }: { installed?: NetcattyInstalledPlugin[] }) {
+export function PluginMarketplace({ installed = [], toolbarContainer, noVault }: { noVault?: boolean; installed?: NetcattyInstalledPlugin[]; toolbarContainer?: HTMLElement | null }) {
   const [selected, setSelected] = useState<string | null>(null);
   const catalog = usePluginCatalog(selected);
-  return <PluginMarketplaceContent catalog={catalog} installed={installed} selected={selected} onSelect={setSelected} />;
+  return <PluginMarketplaceContent catalog={catalog} installed={installed} selected={selected} onSelect={setSelected} toolbarContainer={toolbarContainer} noVault={noVault} />;
 }
 
 // The browser owns only presentation state; installation and README policy stay in the existing hook.
-export function PluginMarketplaceContent({ catalog, installed, selected, onSelect }: {
+export function PluginMarketplaceContent({ catalog, installed, selected, onSelect, toolbarContainer, noVault }: {
+  noVault?: boolean;
+  toolbarContainer?: HTMLElement | null;
   catalog: ReturnType<typeof usePluginCatalog>;
   installed: NetcattyInstalledPlugin[];
   selected: string | null;
@@ -25,23 +29,19 @@ export function PluginMarketplaceContent({ catalog, installed, selected, onSelec
   const { t } = useI18n();
   const [search, setSearch] = useState('');
   const listRef = useRef<HTMLDivElement>(null);
-  const detailRef = useRef<HTMLElement>(null);
+  const detailRef = useRef<HTMLHeadingElement>(null);
   const lastSelection = useRef<string | null>(null);
-  const listScroll = useRef(0);
   const pageScroll = useRef(0);
   const entry = catalog.entries.find((item) => item.id === selected);
   const filtered = filterPluginCatalog(catalog.entries, search);
   const installedEntry = installed.find((item) => item.id === entry?.id);
   const choose = (id: string) => {
-    listScroll.current = listRef.current?.scrollTop ?? 0;
-    if (!entry) pageScroll.current = listRef.current?.closest('[data-settings-scroll-pane]')?.scrollTop ?? 0;
+    const pane = listRef.current?.closest<HTMLElement>('[data-settings-scroll-pane]');
+    pageScroll.current = pane?.scrollTop ?? 0;
     lastSelection.current = id;
     onSelect(id);
     requestAnimationFrame(() => {
-      detailRef.current?.scrollTo?.(0, 0);
-      const container = listRef.current?.closest<HTMLElement>('.plugin-marketplace');
-      const pane = listRef.current?.closest('[data-settings-scroll-pane]');
-      if (container && container.clientWidth < 820 && pane) pane.scrollTop = 0;
+      if (pane) pane.scrollTop = 0;
       detailRef.current?.focus({ preventScroll: true });
     });
   };
@@ -49,7 +49,6 @@ export function PluginMarketplaceContent({ catalog, installed, selected, onSelec
     onSelect(null);
     requestAnimationFrame(() => {
       if (listRef.current) {
-        listRef.current.scrollTop = listScroll.current;
         const pane = listRef.current.closest('[data-settings-scroll-pane]');
         if (pane) pane.scrollTop = pageScroll.current;
         const button = Array.from(listRef.current.querySelectorAll<HTMLButtonElement>('[data-plugin-id]'))
@@ -58,13 +57,14 @@ export function PluginMarketplaceContent({ catalog, installed, selected, onSelec
       }
     });
   };
+  const refresh = !entry && <Button variant="outline" size="sm" disabled={catalog.listStatus === 'loading'} onClick={catalog.retryList}>{t('common.refresh')}</Button>;
   return <section className="plugin-marketplace space-y-4" aria-label={t('settings.plugins.market.title')}>
-    <p className="text-xs text-muted-foreground">{t('settings.plugins.market.note')}</p>
+    {toolbarContainer ? createPortal(<><PluginStatus noVault={noVault} offlineError={catalog.listError} retry={catalog.retryList} />{refresh}</>, toolbarContainer) : <div className="flex items-center gap-2"><PluginStatus noVault={noVault} offlineError={catalog.listError} retry={catalog.retryList} />{refresh}</div>}
     {catalog.error && <p role="alert" className="text-xs text-destructive">{catalog.error}</p>}
-    <div className={`plugin-marketplace-browser${entry ? ' plugin-marketplace-browser--selected' : ''}`}>
-      <div className="plugin-marketplace-catalog space-y-3" ref={listRef}>
-        <Input value={search} onChange={(event) => setSearch(event.target.value)} placeholder={t('settings.plugins.market.search')} aria-label={t('settings.plugins.market.search')} />
-        {catalog.listStatus === 'ready' && <p className="text-xs text-muted-foreground" aria-live="polite">{t('settings.plugins.market.results', { count: filtered.length })}</p>}
+    <div className="plugin-marketplace-browser">
+      {!entry && <div className="plugin-marketplace-catalog space-y-3" ref={listRef}>
+        <div className="flex items-center gap-3"><Input value={search} onChange={(event) => setSearch(event.target.value)} placeholder={t('settings.plugins.market.search')} aria-label={t('settings.plugins.market.search')} />
+        {catalog.listStatus === 'ready' && <p className="shrink-0 text-xs text-muted-foreground" aria-live="polite">{t('settings.plugins.market.results', { count: filtered.length })}</p>}</div>
         {catalog.listStatus === 'ready' && catalog.entries.length > 0 && filtered.length === 0 && <p className="rounded-lg border border-dashed p-6 text-center text-sm text-muted-foreground">{t('settings.plugins.market.noResults')}</p>}
         {catalog.listStatus === 'loading' && <p className="text-xs text-muted-foreground">{t('settings.plugins.loading')}</p>}
         {catalog.listStatus === 'error' && <div role="alert" className="space-y-2 text-xs text-destructive"><p>{catalog.listError}</p><Button variant="outline" size="sm" onClick={catalog.retryList}>{t('settings.plugins.market.retry')}</Button></div>}
@@ -72,26 +72,26 @@ export function PluginMarketplaceContent({ catalog, installed, selected, onSelec
         <div className="plugin-marketplace-grid">{filtered.map((item) => {
           const isInstalled = installed.some((plugin) => plugin.id === item.id);
           return <button key={item.id} type="button" data-plugin-id={item.id} aria-current={selected === item.id ? 'true' : undefined} onClick={() => choose(item.id)}
-            className={`min-w-0 flex flex-col gap-3 rounded-lg border p-4 text-left ${entry ? '' : 'min-h-[200px]'} transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring ${selected === item.id ? 'border-primary/40 bg-primary/10 text-foreground' : 'border-border bg-card hover:bg-muted/50'}`}>
-            <div className="flex items-start gap-2"><PluginBrandIcon entry={item} size={32} className="mt-0.5 shrink-0 text-muted-foreground" /><span className="min-w-0 break-words text-sm font-semibold">{item.name}</span></div>
+            className="plugin-card min-w-0 flex min-h-[200px] flex-col gap-3 rounded-lg bg-card p-4 text-left focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring">
+            <div className="flex items-center gap-3"><span className="flex h-8 w-8 shrink-0 items-center justify-center"><PluginBrandIcon entry={item} size={32} className="text-muted-foreground" /></span><span className="min-w-0 break-words text-sm font-semibold leading-5">{item.name}</span></div>
             <p className="break-words text-xs text-muted-foreground">{item.author}</p>
             <p className="line-clamp-3 break-words text-sm leading-5 text-muted-foreground">{item.description}</p>
             <div className="mt-auto flex flex-wrap items-center justify-between gap-2 pt-1 text-xs text-muted-foreground"><span>{item.version} · {item.license}</span><span className="text-foreground">{t('settings.plugins.manager.details')}</span></div>
-            <div className="flex flex-wrap gap-2 text-xs text-muted-foreground">{isInstalled && <span className="rounded bg-muted px-2 py-0.5 text-foreground">{t('settings.plugins.market.installed')}</span>}{!item.artifact && <span className="rounded border px-2 py-0.5">{t('settings.plugins.market.sourceBadge')}</span>}</div>
+            <div className="flex flex-wrap gap-2 text-xs text-muted-foreground">{isInstalled && <span className="rounded bg-muted px-2 py-0.5 text-foreground">{t('settings.plugins.market.installed')}</span>}{!item.artifact && <span className="rounded bg-muted/40 px-2 py-0.5">{t('settings.plugins.market.sourceBadge')}</span>}</div>
           </button>;
         })}</div>
-      </div>
-      {entry && <article key={entry.id} ref={detailRef} tabIndex={-1} aria-label={entry.name} className="plugin-marketplace-detail min-w-0 space-y-5 rounded-lg border bg-card p-4 focus:outline-none">
+      </div>}
+      {entry && <article key={entry.id} aria-label={entry.name} className="plugin-marketplace-detail mx-auto w-full max-w-[920px] min-w-0 space-y-6 focus:outline-none">
         <Button variant="ghost" size="sm" onClick={back}><ArrowLeft size={14} className="mr-2" />{t('settings.plugins.market.back')}</Button>
-        <div className="space-y-2"><div className="flex items-center gap-3"><PluginBrandIcon entry={entry} size={48} /><h4 className="break-words text-xl font-semibold">{entry.name}</h4></div><p className="text-xs text-muted-foreground">{entry.author} · {entry.version} · {entry.license}</p>
+        <div className="space-y-2"><div className="flex items-center gap-3"><PluginBrandIcon entry={entry} size={48} /><h4 ref={detailRef} tabIndex={-1} className="break-words text-xl font-semibold focus:outline-none">{entry.name}</h4></div><p className="text-xs text-muted-foreground">{entry.author} · {entry.version} · {entry.license}</p>
           {installedEntry && <p className="text-xs text-muted-foreground">{t('settings.plugins.market.installed')} · {installedEntry.activeVersion} · {t(installedEntry.enabled ? 'settings.plugins.manager.enabled' : 'settings.plugins.manager.disabled')}</p>}
         </div>
         {installedEntry?.runtime?.lastError && <p role="status" className="break-words text-xs text-destructive">{t('settings.plugins.manager.lastError')}: {installedEntry.runtime.lastError}</p>}
         <p className="text-sm leading-6 text-muted-foreground">{entry.description}</p>
         <a className="block break-all text-xs text-primary underline underline-offset-4" href={`https://github.com/${entry.repository}/tree/${entry.commit}`} target="_blank" rel="noopener noreferrer">{entry.repository} @ {entry.commit.slice(0, 12)}</a>
-        {entry.artifact ? <div className="space-y-2"><p className="text-xs text-muted-foreground">{t('settings.plugins.market.installNote')}</p><Button size="sm" disabled={catalog.busy} onClick={() => void catalog.install(entry.id)}>{t('settings.plugins.market.install')}</Button></div> : <p className="rounded-lg bg-muted/40 p-3 text-xs leading-5">{t('settings.plugins.market.sourceOnly')}</p>}
-        <SettingCard padded><h4 className="mb-3 text-sm font-semibold">{t('settings.plugins.market.manifest')}</h4><PluginPackageDetails plugin={{ id: entry.id, activeVersion: entry.version, enabled: false, manifest: entry.manifest, archiveSha256: entry.artifact?.sha256, runtime: { status: 'stopped', kind: null, lastError: null, quarantinedAt: null } }} /></SettingCard>
-        <div className="min-w-0 border-t pt-4"><h4 className="text-sm font-semibold">README</h4><p className="mt-2 text-xs text-muted-foreground">{t('settings.plugins.market.readmeNote')}</p>{catalog.readmeStatus === 'loading' && <p className="mt-3 text-xs text-muted-foreground">{t('settings.plugins.loading')}</p>}
+        {entry.artifact ? <div className="space-y-2"><p className="text-xs text-muted-foreground">{t('settings.plugins.market.installNote')}</p>{catalog.listError && <p role="status" className="text-xs text-muted-foreground">{t('settings.plugins.market.offlineShort')}</p>}<Button size="sm" disabled={catalog.busy || Boolean(catalog.listError)} onClick={() => void catalog.install(entry.id)}>{t('settings.plugins.market.install')}</Button></div> : <div className="flex items-center gap-1 text-xs text-muted-foreground"><span>{t('settings.plugins.market.sourceBadge')}</span><PluginInfo label={t('settings.plugins.market.sourceBadge')}>{t('settings.plugins.market.sourceOnly')}</PluginInfo></div>}
+        <section><h4 className="mb-3 text-sm font-semibold">{t('settings.plugins.market.manifest')}</h4><PluginPackageDetails plugin={{ id: entry.id, activeVersion: entry.version, enabled: false, manifest: entry.manifest, archiveSha256: entry.artifact?.sha256, runtime: { status: 'stopped', kind: null, lastError: null, quarantinedAt: null } }} /></section>
+        <div className="min-w-0 border-t pt-4"><div className="flex items-center gap-1"><h4 className="text-sm font-semibold">README</h4><PluginInfo label={t('settings.plugins.market.readmeInfo')}>{t('settings.plugins.market.readmeNote')}</PluginInfo></div>{catalog.readmeStatus === 'loading' && <p className="mt-3 text-xs text-muted-foreground">{t('settings.plugins.loading')}</p>}
           {catalog.readmeStatus === 'error' && <div role="alert" className="mt-3 space-y-2 text-xs text-destructive"><p>{catalog.readmeError}</p><Button variant="outline" size="sm" onClick={catalog.retryReadme}>{t('settings.plugins.market.retry')}</Button></div>}
           {catalog.readmeStatus === 'ready' && (catalog.readme?.trim() ? <PluginReadme markdown={catalog.readme} /> : <p className="mt-3 text-xs text-muted-foreground">{t('settings.plugins.market.emptyReadme')}</p>)}
         </div>

components/settings/tabs/PluginPackageManager.tsx

@@ -75,14 +75,13 @@ export function PluginPackageManager({ manager, onSelectionChange }: { manager:
   const [removing, setRemoving] = useState<string | null>(null);
   if (!manager.available) return null;
   return <section ref={rootRef} className="space-y-4" aria-label={t('settings.plugins.manager.installed')}>
-    <p className="text-xs text-muted-foreground">{t('settings.plugins.manager.preview')}</p>
     {selectedPlugin && <Button variant="ghost" size="sm" onClick={() => choose(null)}><ArrowLeft size={14} className="mr-2" />{t('settings.plugins.manager.installed')}</Button>}
     {!selectedPlugin && manager.plugins.length > 0 && <Input value={search} onChange={(event) => setSearch(event.target.value)} placeholder={t('settings.plugins.market.search')} aria-label={t('settings.plugins.market.search')} />}
     {!selectedPlugin && manager.plugins.length > 0 && visible.length === 0 && <p className="p-6 text-center text-sm text-muted-foreground">{t('settings.plugins.market.noResults')}</p>}
     {manager.error && <p role="alert" className="text-sm text-destructive">{manager.error}</p>}
     {!manager.plugins.length && <div className="rounded-xl border border-dashed border-border p-8 text-center text-sm text-muted-foreground">{t('settings.plugins.manager.empty')}</div>}
     <div className={selectedPlugin ? 'space-y-4' : 'grid grid-cols-[repeat(auto-fill,minmax(min(100%,280px),1fr))] gap-3'}>
-    {visible.map((plugin) => <article key={plugin.id} data-plugin-detail={selectedPlugin ? true : undefined} tabIndex={selectedPlugin ? -1 : undefined} aria-label={nameOf(plugin)} className={`min-w-0 rounded-lg border bg-card p-4 focus:outline-none ${selectedPlugin ? 'space-y-4' : 'flex min-h-[200px] flex-col gap-3'}`}>
+    {visible.map((plugin) => <article key={plugin.id} data-plugin-detail={selectedPlugin ? true : undefined} tabIndex={selectedPlugin ? -1 : undefined} aria-label={nameOf(plugin)} className={`min-w-0 rounded-lg focus:outline-none ${selectedPlugin ? 'space-y-4' : 'plugin-card flex min-h-[200px] flex-col gap-3 bg-card p-4'}`}>
       <div className="flex flex-wrap items-center gap-3">
         <div className="flex h-12 w-12 shrink-0 items-center justify-center"><PluginBrandIcon plugin={plugin} size={32} /></div>
         <button type="button" data-plugin-card={plugin.id} className="min-w-0 flex-1 rounded text-left focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring" aria-expanded={selected === plugin.id} onClick={() => choose(selected === plugin.id ? null : plugin.id)}>

components/settings/tabs/PluginStatus.tsx

@@ -0,0 +1,14 @@
+import React from 'react';
+import { useI18n } from '../../../application/i18n/I18nProvider';
+import { Button } from '../../ui/button';
+import { PluginInfo } from './PluginInfo';
+
+export function PluginStatus({ noVault, offlineError, retry }: { noVault?: boolean; offlineError?: string | null; retry?: () => void }) {
+  const { t } = useI18n();
+  const count = Number(Boolean(noVault)) + Number(Boolean(offlineError));
+  const explanation = <>{noVault && <p>{t('settings.plugins.manager.noVault')}</p>}{offlineError && <><p>{t('settings.plugins.market.offline')}</p><p className="break-words">{offlineError}</p></>}</>;
+  const label = count ? `${t('settings.plugins.info')} · ${t('settings.plugins.status', { count })}` : t('settings.plugins.info');
+  const help = <><p>{t('settings.plugins.manager.preview')}</p><p>{t('settings.plugins.market.note')}</p></>;
+  const preview = <>{count > 0 && <p>{t('settings.plugins.status', { count })}</p>}{explanation}{help}</>;
+  return <PluginInfo label={label} badgeCount={count} previewContent={preview}>{explanation}{offlineError && retry && <Button variant="outline" size="sm" onClick={retry}>{t('settings.plugins.market.retry')}</Button>}{count > 0 && <hr className="border-border/60" />}{help}</PluginInfo>;
+}

components/settings/tabs/SettingsPluginsTab.tsx

@@ -3,6 +3,7 @@ import { PluginManagementDialog } from './PluginManagementDialog';
 import { PluginMarketplace } from './PluginMarketplace';
 import { PluginPackageManager } from './PluginPackageManager';
 import { FolderOpen } from 'lucide-react';
+import { PluginStatus } from './PluginStatus';
 import React, { useEffect, useMemo, useState } from 'react';
 
 import { normalizePluginKeyboardEvent } from '../../../application/state/pluginKeybindings';
@@ -286,6 +287,7 @@ export function PluginSettingField({
 function PluginManagementContent({ handoff }: { handoff: (action: () => void) => void }) {
   const { t } = useI18n();
   const manager = usePluginManager();
+  const [catalogToolbar, setCatalogToolbar] = useState<HTMLDivElement | null>(null);
   const [selectedInstalled, setSelectedInstalled] = useState<string | null>(null);
   const [pluginView, setPluginView] = useState<'installed' | 'marketplace'>('installed');
   const availableFonts = useAvailableFonts();
@@ -314,10 +316,13 @@ function PluginManagementContent({ handoff }: { handoff: (action: () => void) =>
             <TabsTrigger value="installed">{t('settings.plugins.manager.installed')} <span className="ml-2 text-muted-foreground">{manager.plugins.length}</span></TabsTrigger>
             <TabsTrigger value="marketplace">{t('settings.plugins.market.title')}</TabsTrigger>
           </TabsList>
+          <div className="flex items-center gap-2">
+          {pluginView === 'installed' && <PluginStatus noVault={manager.credentialStorageAvailable === false} />}
+          <div ref={setCatalogToolbar} className="flex items-center gap-2" />
           <Button variant="outline" size="sm" disabled={!manager.available || manager.busy} onClick={() => { setPluginView('installed'); void manager.importPackage(); }}><FolderOpen size={14} className="mr-2" />{t('settings.plugins.manager.import')}</Button>
+          </div>
         </div>
-        {manager.credentialStorageAvailable === false && <p role="status" className="text-xs text-muted-foreground">{t('settings.plugins.manager.noVault')}</p>}
-        <TabsContent value="marketplace" className="m-0 space-y-6"><PluginMarketplace installed={manager.plugins} /></TabsContent>
+        <TabsContent value="marketplace" className="m-0 space-y-6"><PluginMarketplace installed={manager.plugins} toolbarContainer={catalogToolbar} noVault={manager.credentialStorageAvailable === false} /></TabsContent>
         <TabsContent value="installed" className="m-0 space-y-6">
         <PluginPackageManager manager={manager} onSelectionChange={setSelectedInstalled} />
         {contextualScopes.size > 0 && (

components/settings/tabs/plugin-marketplace.css

@@ -1,13 +1,9 @@
-/* Container breakpoints account for the Settings sidebar, unlike viewport breakpoints. */
-.plugin-marketplace { container-type: inline-size; }
-.plugin-marketplace-browser { display: grid; gap: 16px; min-width: 0; }
+.plugin-marketplace-browser { min-width: 0; }
 .plugin-marketplace-catalog { min-width: 0; }
-.plugin-marketplace-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); gap: 12px; }
-.plugin-marketplace-browser--selected .plugin-marketplace-catalog { display: none; }
+.plugin-marketplace-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 280px), 1fr)); gap: 16px; }
+/* Details use only the manager's main scrolling surface at every width. */
 .plugin-marketplace-detail { overflow-wrap: anywhere; }
-@container (min-width: 820px) {
-  .plugin-marketplace-browser--selected { grid-template-columns: 248px minmax(0, 1fr); align-items: start; }
-  .plugin-marketplace-browser--selected .plugin-marketplace-catalog { display: block; max-height: min(680px, 65vh); overflow-y: auto; padding: 2px; }
-  .plugin-marketplace-browser--selected .plugin-marketplace-grid { grid-template-columns: minmax(0, 1fr); }
-  .plugin-marketplace-browser--selected .plugin-marketplace-detail { max-height: min(680px, 65vh); overflow-y: auto; }
-}
+.plugin-card { box-shadow: 0 1px 4px hsl(var(--foreground) / 0.06); }
+.plugin-card:hover { box-shadow: 0 2px 8px hsl(var(--foreground) / 0.09); }
+.dark .plugin-card { background: hsl(var(--muted) / 0.2); box-shadow: none; }
+.dark .plugin-card:hover { background: hsl(var(--muted) / 0.3); box-shadow: none; }

docs/plugin-platform/registry-client.md

@@ -0,0 +1,84 @@
+# Official static distribution client
+
+Community starts at the fixed main-process endpoint
+`https://plugins.netcatty.app/v1/snapshot.json`. The renderer cannot choose an
+endpoint. All automatic catalog, README and potential package reads allow only
+that exact HTTPS origin: no credentials, query, fragment, noncanonical URL or
+redirect. No GitHub API/raw/avatar/release fallback exists. Explicit user-opened
+source links may still open GitHub in an external browser.
+
+## Snapshot contract
+
+This client implements the version-1 contract from
+`binaricat/netcatty-plugins@7bfe23e5627e16ba63806de6dded5b2667c02984`.
+The source catalog/index remain unchanged; **no `readmeAsset` field is added**.
+
+The pointer contains `schemaVersion: 1`, `registryCommit`, `snapshotId`, and
+`catalog`, `index`, `delivery` references, each `{path, sha256, size}`. Paths must
+be `/snapshots/<snapshotId>/<name>.json`; `snapshotId` equals the raw delivery
+SHA-256. The host checks the pointer before requesting its three documents,
+then checks raw byte counts/hashes, JSON budgets, schemas and cross-document
+identity. The three documents must all validate before replacing any cache.
+
+Delivery contains `schemaVersion`, `registryCommit`, `catalogSha256`,
+`indexSha256`, `sourceLockSha256`, `builderSha256` and `plugins`. Each item matches
+one exact catalog `id/version/repository/commit` tuple and supplies `readme`,
+`iconLight`, `iconDark`, `avatar`, `artifact`. Asset references are
+`{path, sha256, size}`, with `/assets/<sha256>.md` for README and `.png`/`.webp`
+for brand icons. This v1 publishing schema requires **avatar and artifact to
+be null**. The client rejects unsupported delivery metadata rather than
+inventing installable packages or deriving a GitHub avatar URL.
+
+Index is validated with its pinned schema. Plugin/version identities must be
+unique; each catalog entry must exactly equal the index's current, non-withdrawn,
+source-only entry. Withdrawal does not disable, uninstall or delete any existing
+plugin: this is catalog admission, not a remote installed-code kill switch.
+
+Schemas are vendored under `electron/plugins/distribution/`, with provenance and
+fixtures described there. All schema references resolve locally; schema validation
+does not fetch GitHub or netcatty.com.
+
+## Bounds, cache and selection
+
+Pointer reads are bounded to 16 KiB, each JSON document to 2 MiB, and each README
+to 256 KiB. Reads time out after 30 seconds. Whole JSON values retain the existing
+128-level / 100,000-value / finite-number boundary. Catalogs contain at most 1,000
+entries. Existing manifest identity, license and browser-only policies remain.
+
+The host prepares private entries, private delivery resources and all public
+selection tokens before one synchronous cache publication. Parse, integrity,
+schema, clone, tuple or network failures preserve the last complete good snapshot.
+The cache remains **in memory for this app session**; a fresh offline launch lists
+bundled examples. No new disk database, sync record or credential is introduced.
+
+A host-generated selection token binds the complete entry and its delivery item.
+This prevents silent selection changes; it is **not a signature**. README requests
+capture the matched static reference and verify its exact byte count and digest.
+Missing/offline snapshots show an error/Retry; they never synthesize a raw GitHub URL.
+README HTML and remote images remain inert in the existing safe renderer.
+
+The current v1 distribution cannot install packages. A later publishing/client
+schema revision must jointly introduce reviewed package mirroring, keep source
+manifest/hash admission, and recheck the current pointer and fresh root withdrawal
+ledger before any install. A historical snapshot alone cannot establish availability.
+The existing lower-level package downloader accepts only official static URLs and
+exact SHA-256 bytes; it does not relax those future gates or auto-enable code.
+
+## Network inventory
+
+| Path | Automatic source | Failure behavior |
+| --- | --- | --- |
+| Pointer / manual refresh | Fixed `/v1/snapshot.json` | Complete session cache, or bundled source-only entries |
+| Catalog/index/delivery | Pointer-bound same-origin immutable paths | Reject partial or mixed snapshots |
+| README details | Exact delivery `/assets/<hash>.md` | Visible error/Retry, no upstream fallback |
+| Uninstalled brand icons | Existing reviewed bundled previews | Default icon; delivery icon metadata validated but not fetched by UI |
+| Installed brand icons | Host-owned local package decoder | Default icon; no activation/network request |
+| Author avatars | Not implemented; delivery v1 requires null | Existing local presentation; no avatar lookup |
+| Package artifacts | Not published or admitted by delivery v1 | Source-only; no download action fabricated |
+| Source/README links | Explicit user-opened external HTTPS link | May open GitHub; no background dependency |
+
+The real PR3 bootstrap is retained as a test fixture with its original bytes and
+hashes. Tests also verify its brand-icon asset bytes; this does not claim a new
+remote icon renderer. The static publisher is not a proxy. Client tests do not
+prove deployment, mainland reachability or successful native CDN access. Native
+QA must independently verify the published endpoint and visible failure state.

electron/pluginRuntime.test.cjs

@@ -27,3 +27,5 @@ require("./plugins/utilityPluginRuntime.test.cjs");
 require('./plugins/brandIconService.test.cjs');
 
 require('./plugins/settingsViewFixture.test.cjs');
+
+require('./plugins/registryCatalogService.test.cjs');

electron/plugins/catalogService.cjs

@@ -8,20 +8,37 @@ const { getTempFilePath } = require("../bridges/tempDirBridge.cjs");
 const { createDefinitionValidator, formatValidationErrors } = require("./contractValidator.cjs");
 const validateManifest = createDefinitionValidator("PluginManifest");
 const { assertCatalogManifest } = require("./catalogPolicy.cjs");
+const { assertPluginJsonValue } = require("./jsonBoundary.cjs");
+const MAX_CATALOG_BYTES = 2 * 1024 * 1024;
+const CATALOG_FIELDS = new Set(["id", "version", "name", "description", "author", "repository", "commit", "license", "readme", "manifest", "artifact"]);
 
-const DOWNLOAD_HOSTS = new Set(["github.com", "raw.githubusercontent.com", "release-assets.githubusercontent.com", "objects.githubusercontent.com"]);
+const DISTRIBUTION_ORIGIN = "https://plugins.netcatty.app";
 function assertDownloadUrl(value) {
+  if (typeof value !== "string" || /[\u0000-\u0020\u007f\\%?#]/u.test(value)) {
+    throw new Error("Catalog download URL is not an approved HTTPS static distribution source");
+  }
   const url = new URL(value);
-  if (url.protocol !== "https:" || url.username || url.password || url.port || !DOWNLOAD_HOSTS.has(url.hostname)) {
-    throw new Error("Catalog download URL is not an approved HTTPS GitHub source");
+  if (url.origin !== DISTRIBUTION_ORIGIN || url.username || url.password || url.port
+    || url.href !== value || url.pathname.split("/").some((part) => part === "." || part === "..")) {
+    throw new Error("Catalog download URL is not an approved HTTPS static distribution source");
   }
   return url.href;
 }
+function assertReadmeSource(entry) {
+  if (typeof entry.readme !== "string" || /[\u0000-\u001f\u007f\\%?#]/u.test(entry.readme)
+    || entry.readme.split("/").some((segment) => !segment || segment === "." || segment === "..")) {
+    throw new Error("Invalid or unpinned README path");
+  }
+  if (entry.repository.split("/").some((part) => part === "." || part === "..")) {
+    throw new Error("README source escapes the pinned commit");
+  }
+}
 function validateCatalog(entries) {
+  assertPluginJsonValue(entries, { maxBytes: MAX_CATALOG_BYTES });
   if (!Array.isArray(entries) || entries.length > 1000) throw new Error("Invalid plugin catalog");
   const ids = new Set();
   for (const entry of entries) {
-    if (!entry || !/^[a-z0-9][a-z0-9.-]+$/u.test(entry.id) || ids.has(entry.id)
+    if (!entry || Object.keys(entry).some((key) => !CATALOG_FIELDS.has(key)) || ["id", "version", "name", "description", "author", "repository", "commit", "license", "readme"].some((key) => typeof entry[key] !== "string" || entry[key].length > 4096) || !/^[a-z0-9][a-z0-9.-]+$/u.test(entry.id) || ids.has(entry.id)
       || !/^[A-Za-z0-9_.-]+\/[A-Za-z0-9_.-]+$/u.test(entry.repository)
       || !/^[a-f0-9]{40}$/u.test(entry.commit)
       || !entry.license || !entry.author || !entry.name
@@ -29,49 +46,53 @@ function validateCatalog(entries) {
       || entry.readme.split("/").some((p) => !p || p === "." || p === "..") || /[\\%?#\0]/u.test(entry.readme)) {
       throw new Error("Invalid or unpinned plugin catalog entry");
     }
+    assertReadmeSource(entry);
     if (!validateManifest(entry.manifest)) throw new Error(`Catalog manifest is invalid: ${formatValidationErrors(validateManifest.errors)}`);
     assertCatalogManifest(entry.manifest, entry);
     ids.add(entry.id);
-    if (entry.artifact) {
-      assertDownloadUrl(entry.artifact.url);
-      if (!/^[a-f0-9]{64}$/u.test(entry.artifact.sha256)) throw new Error("Catalog artifact requires SHA-256");
+    for (const field of ["artifact"]) {
+      if (!Object.hasOwn(entry, field)) continue;
+      const asset = entry[field];
+      if (!asset || typeof asset !== "object" || Array.isArray(asset)
+        || Object.keys(asset).some((key) => key !== "url" && key !== "sha256")
+        || typeof asset.url !== "string" || typeof asset.sha256 !== "string") {
+        throw new Error(`Invalid catalog ${field} metadata`);
+      }
+      assertDownloadUrl(asset.url);
+      if (!/^[a-f0-9]{64}$/u.test(asset.sha256)) throw new Error(`Catalog ${field} requires SHA-256`);
     }
   }
   return entries;
 }
-async function fetchBounded(url, limit, fetchImpl = fetch, maxRedirects = 4) {
+async function fetchBounded(url, limit, fetchImpl = fetch) {
   const signal = AbortSignal.timeout(30_000);
-  for (let redirects = 0; redirects <= maxRedirects; redirects++) {
-    const response = await fetchImpl(assertDownloadUrl(url), { redirect: "manual", signal, credentials: "omit", referrerPolicy: "no-referrer" });
-    if ([301, 302, 303, 307, 308].includes(response.status)) {
-      await response.body?.cancel();
-      url = new URL(response.headers.get("location"), url).href;
-      continue;
-    }
-    if (!response.ok) { await response.body?.cancel(); throw new Error(`Catalog download failed (${response.status})`); }
-    if (Number(response.headers.get("content-length")) > limit) {
-      await response.body?.cancel(); throw new Error("Catalog download exceeds size limit");
-    }
-    const reader = response.body?.getReader();
-    if (!reader) throw new Error("Catalog download has no body");
-    const chunks = [];
-    let size = 0;
-    try {
-      for (;;) {
-        const { done, value } = await reader.read();
-        if (done) break;
-        size += value.byteLength;
-        if (size > limit) throw new Error("Catalog download exceeds size limit");
-        chunks.push(Buffer.from(value));
-      }
-      return Buffer.concat(chunks, size);
-    } finally { await reader.cancel(); }
+  const response = await fetchImpl(assertDownloadUrl(url), { redirect: "manual", signal, credentials: "omit", referrerPolicy: "no-referrer" });
+  if ([301, 302, 303, 307, 308].includes(response.status)) {
+    await response.body?.cancel();
+    throw new Error("Catalog redirects are not allowed");
   }
-  throw new Error("Too many catalog redirects");
+  if (!response.ok) { await response.body?.cancel(); throw new Error(`Catalog download failed (${response.status})`); }
+  if (Number(response.headers.get("content-length")) > limit) {
+    await response.body?.cancel(); throw new Error("Catalog download exceeds size limit");
+  }
+  const reader = response.body?.getReader();
+  if (!reader) throw new Error("Catalog download has no body");
+  const chunks = [];
+  let size = 0;
+  try {
+    for (;;) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      size += value.byteLength;
+      if (size > limit) throw new Error("Catalog download exceeds size limit");
+      chunks.push(Buffer.from(value));
+    }
+    return Buffer.concat(chunks, size);
+  } finally { await reader.cancel(); }
 }
 class PluginCatalogService {
   constructor(options) {
-    this.entries = validateCatalog(structuredClone(options.entries ?? catalog));
+    this.entries = structuredClone(validateCatalog(options.entries ?? catalog));
     this.fetch = options.fetch ?? fetch;
     this.getTempFilePath = options.getTempFilePath ?? getTempFilePath;
     this.manager = options.manager;
@@ -83,11 +104,6 @@ class PluginCatalogService {
     if (!entry) throw new Error("Plugin is not in the curated catalog");
     return entry;
   }
-  async readme(id) {
-    const entry = this.get(id);
-    const url = `https://raw.githubusercontent.com/${entry.repository}/${entry.commit}/${entry.readme}`;
-    return (await fetchBounded(url, 256 * 1024, this.fetch, 0)).toString("utf8");
-  }
   async install(id) {
     const entry = this.get(id);
     if (!entry.artifact) throw new Error("This source example has no published package; build and import locally");
@@ -107,4 +123,4 @@ class PluginCatalogService {
     }
   }
 }
-module.exports = { PluginCatalogService, assertDownloadUrl, fetchBounded, validateCatalog };
+module.exports = { PluginCatalogService, assertDownloadUrl, fetchBounded, validateCatalog, assertReadmeSource, MAX_CATALOG_BYTES, DISTRIBUTION_ORIGIN };

electron/plugins/catalogService.test.cjs

@@ -24,25 +24,17 @@ test("curated catalog uses pinned public first-party source and rejects advanced
   assert.throws(() => validateCatalog([{ ...entries[0], commit: "main" }]), /unpinned/);
 });
 
-test("README retrieval is bounded and pinned, never follows a redirect to latest", async () => {
-  const requested = [];
-  const service = new PluginCatalogService({ entries, fetch: async (url) => {
-    requested.push(url); return new Response("# First-party example");
-  } });
-  assert.equal(await service.readme(entries[0].id), "# First-party example");
-  assert.equal(requested[0], `https://raw.githubusercontent.com/${entries[0].repository}/${entries[0].commit}/${entries[0].readme}`);
-  service.fetch = async () => new Response(null, { status: 302, headers: { location: "https://raw.githubusercontent.com/a/b/main/README.md" } });
-  await assert.rejects(service.readme(entries[0].id), /redirects/);
-  await assert.rejects(fetchBounded("https://raw.githubusercontent.com/a/b/c", 3, async () => new Response("1234")), /size limit/);
+test("static downloader is bounded and never follows redirects", async () => {
+  await assert.rejects(fetchBounded("https://plugins.netcatty.app/a", 3, async () => new Response("1234")), /size limit/);
   await assert.rejects(fetchBounded("https://127.0.0.1/a", 10), /approved HTTPS/);
-  await assert.rejects(fetchBounded("https://github.com/a", 10, async () => new Response(null, { status: 302, headers: { location: "http://localhost/secret" } })), /approved HTTPS/);
+  await assert.rejects(fetchBounded("https://plugins.netcatty.app/a", 10, async () => new Response(null, { status: 302, headers: { location: "https://github.com/a" } })), /redirects/);
 });
 
 test("catalog install verifies the digest, shares manager installation, and never auto-enables", async (context) => {
   const root = await fs.mkdtemp(path.join(os.tmpdir(), "netcatty-catalog-test-"));
   context.after(() => fs.rm(root, { recursive: true, force: true }));
   const bytes = Buffer.from("synthetic bytes: package validation belongs to PackageStore");
-  const entry = { ...structuredClone(entries[0]), artifact: { url: "https://github.com/example/repo/releases/download/v1/plugin.ncpkg", sha256: createHash("sha256").update(bytes).digest("hex") } };
+  const entry = { ...structuredClone(entries[0]), artifact: { url: "https://plugins.netcatty.app/packages/synthetic.ncpkg", sha256: createHash("sha256").update(bytes).digest("hex") } };
   let installs = 0;
   const service = new PluginCatalogService({ entries: [entry], getTempFilePath: (name) => {
     assert.equal(name, "plugin-catalog-");

electron/plugins/distribution/README.md

@@ -0,0 +1,16 @@
+# Pinned static distribution schemas
+
+`delivery.schema.json` and `index.schema.json` are unmodified UTF-8 files from
+binaricat/netcatty-plugins commit 7bfe23e5627e16ba63806de6dded5b2667c02984
+(PR 3). The host compiles them with the existing local plugin-contract schema;
+no schema reference causes network access.
+
+`../fixtures/static-distribution/` contains that commit's actual
+`distribution/bootstrap/v1/snapshot.json`, snapshot catalog/index/delivery and
+four referenced README/PNG assets. Raw-byte SHA-256 checks in
+`staticDistribution.test.cjs` verify the publisher's supplied pointer and delivery
+hashes; every document and asset is checked against the pointer/sidecar.
+The fixture includes no executable plugin package, avatar or credentials.
+
+Schema revisions must be coordinated with the registry publisher. In particular,
+artifact/avatar are deliberately null in v1; do not expand this consumer alone.

electron/plugins/distribution/delivery.schema.json

@@ -0,0 +1,166 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "Netcatty static delivery v1 (source-only bootstrap)",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "registryCommit",
+    "plugins",
+    "catalogSha256",
+    "indexSha256",
+    "sourceLockSha256",
+    "builderSha256"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "const": 1
+    },
+    "registryCommit": {
+      "type": "string",
+      "pattern": "^[a-f0-9]{40}$"
+    },
+    "plugins": {
+      "type": "array",
+      "maxItems": 1000,
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": [
+          "id",
+          "version",
+          "repository",
+          "commit",
+          "readme",
+          "iconLight",
+          "iconDark",
+          "avatar",
+          "artifact"
+        ],
+        "properties": {
+          "id": {
+            "type": "string"
+          },
+          "version": {
+            "type": "string"
+          },
+          "repository": {
+            "type": "string"
+          },
+          "commit": {
+            "type": "string",
+            "pattern": "^[a-f0-9]{40}$"
+          },
+          "readme": {
+            "type": "object",
+            "additionalProperties": false,
+            "required": [
+              "path",
+              "sha256",
+              "size"
+            ],
+            "properties": {
+              "path": {
+                "type": "string",
+                "pattern": "^/assets/[a-f0-9]{64}\\.(md|png|webp|ncpkg)$"
+              },
+              "sha256": {
+                "type": "string",
+                "pattern": "^[a-f0-9]{64}$"
+              },
+              "size": {
+                "type": "integer",
+                "minimum": 0,
+                "maximum": 262144
+              }
+            }
+          },
+          "iconLight": {
+            "oneOf": [
+              {
+                "type": "null"
+              },
+              {
+                "type": "object",
+                "additionalProperties": false,
+                "required": [
+                  "path",
+                  "sha256",
+                  "size"
+                ],
+                "properties": {
+                  "path": {
+                    "type": "string",
+                    "pattern": "^/assets/[a-f0-9]{64}\\.(md|png|webp|ncpkg)$"
+                  },
+                  "sha256": {
+                    "type": "string",
+                    "pattern": "^[a-f0-9]{64}$"
+                  },
+                  "size": {
+                    "type": "integer",
+                    "minimum": 0,
+                    "maximum": 262144
+                  }
+                }
+              }
+            ]
+          },
+          "iconDark": {
+            "oneOf": [
+              {
+                "type": "null"
+              },
+              {
+                "type": "object",
+                "additionalProperties": false,
+                "required": [
+                  "path",
+                  "sha256",
+                  "size"
+                ],
+                "properties": {
+                  "path": {
+                    "type": "string",
+                    "pattern": "^/assets/[a-f0-9]{64}\\.(md|png|webp|ncpkg)$"
+                  },
+                  "sha256": {
+                    "type": "string",
+                    "pattern": "^[a-f0-9]{64}$"
+                  },
+                  "size": {
+                    "type": "integer",
+                    "minimum": 0,
+                    "maximum": 262144
+                  }
+                }
+              }
+            ]
+          },
+          "avatar": {
+            "type": "null"
+          },
+          "artifact": {
+            "type": "null"
+          }
+        }
+      }
+    },
+    "catalogSha256": {
+      "type": "string",
+      "pattern": "^[a-f0-9]{64}$"
+    },
+    "indexSha256": {
+      "type": "string",
+      "pattern": "^[a-f0-9]{64}$"
+    },
+    "sourceLockSha256": {
+      "type": "string",
+      "pattern": "^[a-f0-9]{64}$"
+    },
+    "builderSha256": {
+      "type": "string",
+      "pattern": "^[a-f0-9]{64}$"
+    }
+  }
+}

electron/plugins/distribution/index.schema.json

@@ -0,0 +1,194 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "plugins"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "const": 1
+    },
+    "plugins": {
+      "type": "array",
+      "maxItems": 1000,
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": [
+          "id",
+          "current",
+          "versions"
+        ],
+        "properties": {
+          "id": {
+            "type": "string",
+            "minLength": 1,
+            "maxLength": 4096,
+            "pattern": "^[a-z0-9][a-z0-9.-]+$"
+          },
+          "current": {
+            "oneOf": [
+              {
+                "type": "string",
+                "minLength": 1,
+                "maxLength": 4096,
+                "pattern": "^(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)(-[0-9A-Za-z.-]+)?(\\+[0-9A-Za-z.-]+)?$"
+              },
+              {
+                "type": "null"
+              }
+            ]
+          },
+          "versions": {
+            "type": "array",
+            "minItems": 1,
+            "maxItems": 1000,
+            "items": {
+              "type": "object",
+              "additionalProperties": false,
+              "required": [
+                "entry",
+                "distribution",
+                "withdrawal"
+              ],
+              "properties": {
+                "entry": {
+                  "type": "object",
+                  "additionalProperties": false,
+                  "required": [
+                    "id",
+                    "version",
+                    "name",
+                    "description",
+                    "author",
+                    "repository",
+                    "commit",
+                    "license",
+                    "readme",
+                    "manifest"
+                  ],
+                  "properties": {
+                    "id": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096,
+                      "pattern": "^[a-z0-9][a-z0-9.-]+$"
+                    },
+                    "version": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096,
+                      "pattern": "^(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)(-[0-9A-Za-z.-]+)?(\\+[0-9A-Za-z.-]+)?$"
+                    },
+                    "name": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096
+                    },
+                    "description": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096
+                    },
+                    "author": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096
+                    },
+                    "repository": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096,
+                      "pattern": "^[A-Za-z0-9_.-]+/[A-Za-z0-9_.-]+$"
+                    },
+                    "commit": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096,
+                      "pattern": "^[a-f0-9]{40}$"
+                    },
+                    "license": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096
+                    },
+                    "readme": {
+                      "type": "string",
+                      "minLength": 1,
+                      "maxLength": 4096
+                    },
+                    "manifest": {
+                      "$ref": "https://netcatty.com/schemas/plugins/0.1.0-internal.1/plugin-contract.schema.json"
+                    },
+                    "artifact": {
+                      "type": "object",
+                      "additionalProperties": false,
+                      "required": [
+                        "url",
+                        "sha256"
+                      ],
+                      "properties": {
+                        "url": {
+                          "type": "string",
+                          "minLength": 1,
+                          "maxLength": 4096
+                        },
+                        "sha256": {
+                          "type": "string",
+                          "pattern": "^[a-f0-9]{64}$"
+                        }
+                      }
+                    }
+                  }
+                },
+                "distribution": {
+                  "enum": [
+                    "source-only",
+                    "release"
+                  ]
+                },
+                "tag": {
+                  "type": "string",
+                  "pattern": "^[A-Za-z0-9][A-Za-z0-9._-]{0,127}$"
+                },
+                "withdrawal": {
+                  "oneOf": [
+                    {
+                      "type": "null"
+                    },
+                    {
+                      "type": "object",
+                      "additionalProperties": false,
+                      "required": [
+                        "at",
+                        "reason",
+                        "advisory"
+                      ],
+                      "properties": {
+                        "at": {
+                          "type": "string",
+                          "format": "date-time"
+                        },
+                        "reason": {
+                          "type": "string",
+                          "minLength": 1,
+                          "maxLength": 4096
+                        },
+                        "advisory": {
+                          "type": "string",
+                          "pattern": "^https://github.com/"
+                        }
+                      }
+                    }
+                  ]
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}

electron/plugins/distributionSnapshot.cjs

@@ -0,0 +1,107 @@
+"use strict";
+
+const { createHash } = require("node:crypto");
+const { isDeepStrictEqual } = require("node:util");
+const Ajv2020 = require("ajv/dist/2020").default;
+const addFormats = require("ajv-formats").default;
+const { assertPluginJsonValue } = require("./jsonBoundary.cjs");
+const { fetchBounded, validateCatalog, DISTRIBUTION_ORIGIN, MAX_CATALOG_BYTES } = require("./catalogService.cjs");
+const { formatValidationErrors } = require("./contractValidator.cjs");
+const REGISTRY_URL = `${DISTRIBUTION_ORIGIN}/v1/snapshot.json`;
+const SHA256 = /^[a-f0-9]{64}$/u;
+const COMMIT = /^[a-f0-9]{40}$/u;
+const ajv = new Ajv2020({ allErrors: true, strict: false, validateFormats: true });
+addFormats(ajv);
+ajv.addSchema(require("./generated/plugin-contract.schema.json"));
+const validateIndex = ajv.compile(require("./distribution/index.schema.json"));
+const validateDelivery = ajv.compile(require("./distribution/delivery.schema.json"));
+const digest = (bytes) => createHash("sha256").update(bytes).digest("hex");
+const tuple = (entry) => JSON.stringify([entry.id, entry.version, entry.repository, entry.commit]);
+
+function exactKeys(value, keys) {
+  return value && typeof value === "object" && !Array.isArray(value)
+    && Object.keys(value).length === keys.length && keys.every((key) => Object.hasOwn(value, key));
+}
+function assertReference(ref, path, limit) {
+  if (!exactKeys(ref, ["path", "sha256", "size"]) || typeof ref.sha256 !== "string" || !SHA256.test(ref.sha256)
+    || ref.path !== path || !Number.isSafeInteger(ref.size) || ref.size < 0 || ref.size > limit) {
+    throw new Error("Invalid static snapshot resource reference");
+  }
+}
+function parseJson(bytes, label, limit = MAX_CATALOG_BYTES) {
+  const value = JSON.parse(bytes.toString("utf8"));
+  assertPluginJsonValue(value, { maxBytes: limit });
+  if (!value || typeof value !== "object") throw new Error(`Invalid ${label}`);
+  return value;
+}
+function assertPointer(pointer) {
+  if (!exactKeys(pointer, ["schemaVersion", "registryCommit", "snapshotId", "catalog", "index", "delivery"])
+    || pointer.schemaVersion !== 1 || typeof pointer.registryCommit !== "string" || !COMMIT.test(pointer.registryCommit)
+    || typeof pointer.snapshotId !== "string" || !SHA256.test(pointer.snapshotId)) {
+    throw new Error("Invalid static snapshot pointer");
+  }
+  for (const name of ["catalog", "index", "delivery"]) {
+    assertReference(pointer[name], `/snapshots/${pointer.snapshotId}/${name}.json`, MAX_CATALOG_BYTES);
+  }
+  if (pointer.snapshotId !== pointer.delivery.sha256) throw new Error("Snapshot identity does not match delivery hash");
+}
+function assertAsset(ref, extensions) {
+  if (!ref || typeof ref.path !== "string" || !extensions.some((extension) => ref.path === `/assets/${ref.sha256}.${extension}`)) {
+    throw new Error("Invalid static asset path or format");
+  }
+  assertReference(ref, ref.path, 256 * 1024);
+}
+async function fetchVerified(ref, fetchImpl) {
+  const bytes = await fetchBounded(`${DISTRIBUTION_ORIGIN}${ref.path}`, ref.size, fetchImpl);
+  if (bytes.byteLength !== ref.size || digest(bytes) !== ref.sha256) throw new Error("Static resource size or SHA-256 mismatch");
+  return bytes;
+}
+function validateSet(pointer, entries, index, delivery) {
+  validateCatalog(entries);
+  if (!validateIndex(index)) throw new Error(`Invalid distribution index: ${formatValidationErrors(validateIndex.errors)}`);
+  if (!validateDelivery(delivery)) throw new Error(`Invalid static delivery: ${formatValidationErrors(validateDelivery.errors)}`);
+  if (delivery.registryCommit !== pointer.registryCommit || delivery.catalogSha256 !== pointer.catalog.sha256
+    || delivery.indexSha256 !== pointer.index.sha256) throw new Error("Static snapshot documents do not match");
+  // v1 publishing deliberately refuses packages and avatars. Do not extend this
+  // consumer ahead of the reviewed publishing schema or invent installable code.
+  if (entries.some((entry) => entry.artifact)) throw new Error("Static delivery v1 is source-only");
+  const current = new Map();
+  const indexIds = new Set();
+  for (const plugin of index.plugins) {
+    if (indexIds.has(plugin.id)) throw new Error("Duplicate distribution index plugin");
+    indexIds.add(plugin.id);
+    const versions = new Map();
+    for (const version of plugin.versions) {
+      if (version.entry.id !== plugin.id || versions.has(version.entry.version)) throw new Error("Invalid distribution version identity");
+      versions.set(version.entry.version, version);
+    }
+    if (plugin.current !== null) {
+      const version = versions.get(plugin.current);
+      if (!version || version.withdrawal !== null || version.distribution !== "source-only") throw new Error("Current distribution version is missing or withdrawn");
+      current.set(plugin.id, version.entry);
+    }
+  }
+  if (current.size !== entries.length || entries.some((entry) => !isDeepStrictEqual(current.get(entry.id), entry))) {
+    throw new Error("Catalog does not match the current non-withdrawn index");
+  }
+  const resources = new Map();
+  const catalogTuples = new Set(entries.map(tuple));
+  for (const plugin of delivery.plugins) {
+    const key = tuple(plugin);
+    if (!catalogTuples.has(key) || resources.has(key)) throw new Error("Delivery identity does not match catalog tuple");
+    assertAsset(plugin.readme, ["md"]);
+    for (const icon of [plugin.iconLight, plugin.iconDark]) if (icon !== null) assertAsset(icon, ["png", "webp"]);
+    resources.set(key, plugin);
+  }
+  if (resources.size !== entries.length) throw new Error("Missing delivery entry for catalog plugin");
+  return resources;
+}
+async function fetchDistribution(fetchImpl) {
+  const pointer = parseJson(await fetchBounded(REGISTRY_URL, 16 * 1024, fetchImpl), "snapshot pointer", 16 * 1024);
+  assertPointer(pointer);
+  const documents = await Promise.all(["catalog", "index", "delivery"].map(async (name) => parseJson(await fetchVerified(pointer[name], fetchImpl), name)));
+  const [entries, index, delivery] = documents;
+  const resources = validateSet(pointer, entries, index, delivery);
+  return { entries, resources, pointer };
+}
+module.exports = { REGISTRY_URL, fetchDistribution, fetchVerified, tuple, validateSet, assertPointer, assertAsset };

electron/plugins/fixtures/static-distribution/assets/1692573445e3688b4fe3612282becc086b191a034c0609deeaaebf615627c209.md

@@ -0,0 +1,53 @@
+# Hello Netcatty
+
+This package is the runnable internal example for the plugin API. Package and install it to exercise native settings,
+command-palette contributions, lazy command and Provider activation,
+localization, terminal completion/decoration Providers, and the runtime SDK.
+
+From the repository root:
+
+```bash
+npm run build:plugin-packages
+node packages/plugin-cli/dist/cli.js validate examples/plugins/hello-netcatty
+node packages/plugin-cli/dist/cli.js compatibility examples/plugins/hello-netcatty --netcatty 0.0.0
+node packages/plugin-cli/dist/cli.js pack examples/plugins/hello-netcatty --out /tmp/hello-netcatty.ncpkg
+```
+
+After installation, change **Greeting** under **Settings → Plugins**, then run
+**Examples: Say Hello** from the command palette. The setting is read through
+the host settings broker and the command handler is registered inside the
+sandboxed plugin runtime. Type `netc` at a shell prompt to exercise the bounded
+completion Provider, and print `Hello from Netcatty` to exercise the declarative
+decoration Provider. Neither Provider receives raw xterm objects or sensitive
+terminal input/output streams.
+
+## Import and inspect
+
+Launch the normal browser-only plugin build using a fresh Electron
+user-data directory for demonstrations. In **Settings > Plugins**, choose
+**Import .ncpkg**, select the generated archive, and open its details. Review the
+manifest permissions, engine ranges and SHA-256, then choose **Enable**. Native
+permission prompts still mediate activation and sensitive operations.
+
+Importing an update is a manual action and leaves it disabled, including when
+the previous version was enabled. Review the new package before enabling it.
+Changing unsigned package contents changes its security principal; previous
+persistent grants are not transferred to different bytes.
+
+An incompatible application/API upgrade disables installed plugins before
+publishing their contributions. The reason remains in the installed list, and
+package files and local data remain available. Returning to a compatible host
+requires explicit re-enable. Uninstall is different: package code and local KV
+are deleted; user-owned settings, secret storage and sync sidecars are retained.
+
+For a synthetic demonstration, use only this first-party example, change the
+Greeting, invoke **Examples: Say Hello**, disable/re-enable, restart the app and
+inspect the package again. Do not connect real hosts or a cloud account. The
+existing greeting setting is local; declaring `sync: true` on a non-secret
+setting opts it into the existing encrypted settings sidecar. Generic SDK KV
+storage does not sync.
+
+For a demonstration without terminal permissions, use `examples/plugins/starter-netcatty`.
+Enabling this lazy example does not grant permissions: required permissions are
+requested before its first command/provider activation, and optional permissions
+when used. Never treat Enabled as a security certification or grant.

electron/plugins/fixtures/static-distribution/assets/d685ec68558c81705f03195ca35a0a62ea6ec75d8837d5ddb5b5a970890aae6e.md

@@ -0,0 +1,37 @@
+# Plugin Starter
+
+A minimal first-party browser plugin for learning import, settings and lifecycle.
+It requests `commands`, `settings.read`, `menus` and `views`: no terminal text, host credentials,
+network, files, secrets or advanced Node access. It works without OS key storage.
+Permission declarations are not grants; follow the app's normal mediation.
+
+From the repository root:
+
+```sh
+npm run build:plugin-packages
+node packages/plugin-cli/dist/cli.js validate examples/plugins/starter-netcatty
+node packages/plugin-cli/dist/cli.js pack examples/plugins/starter-netcatty --out /tmp/starter-netcatty.ncpkg
+```
+
+Start the actual app normally with a fresh test profile; no development flag is
+needed. Open **Settings > Plugins > Open plugin manager > Installed**, import the package, inspect its
+permissions and enable it. Change **Greeting**, then find **Starter: Greeting Panel** (入门：问候面板)
+in the command palette. Review the normal permission prompts, then click
+**Show greeting** to see the exact preference in the sandboxed panel.
+**Starter: Read Greeting** is also listed and refreshes an already-open panel.
+The panel inserts text using `textContent`, never HTML. It does not write to
+a terminal or connect to a host. Denied permissions remain denied.
+
+Disable, restart and re-enable to verify the preference persists. Re-importing
+the same package leaves it disabled for review. Uninstall removes code and local
+KV; user-owned settings remain. The greeting is local only, not cloud-synced.
+
+The separate Hello Netcatty example demonstrates terminal providers and requests
+terminal permissions. Use this Starter for the default no-sensitive-access demo.
+
+
+Version 0.1.2 adds light/dark PNG brand icons in `assets/`. Displaying these
+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).

electron/plugins/fixtures/static-distribution/catalog.json

@@ -0,0 +1,195 @@
+[
+  {
+    "id": "com.netcatty.starter",
+    "version": "0.1.2",
+    "name": "Plugin Starter",
+    "description": "First-party greeting panel, local settings and commands, without terminal or secret access.",
+    "author": "Netcatty",
+    "repository": "binaricat/Netcatty",
+    "commit": "f4a6b205adca486d4e9cda0270e13a9ff0afd7be",
+    "license": "GPL-3.0-or-later",
+    "readme": "examples/plugins/starter-netcatty/README.md",
+    "manifest": {
+      "manifestVersion": 1,
+      "id": "com.netcatty.starter",
+      "name": "starter-netcatty",
+      "displayName": {
+        "en": "Plugin Starter",
+        "zh-CN": "插件入门"
+      },
+      "description": "First-party settings and command example. No terminal, network, filesystem or secret access.",
+      "version": "0.1.2",
+      "publisher": "netcatty",
+      "license": "GPL-3.0-or-later",
+      "engines": {
+        "netcatty": ">=0.0.0",
+        "api": ">=0.1.0-internal.1 <0.2.0"
+      },
+      "main": {
+        "browser": "dist/index.js"
+      },
+      "activationEvents": [
+        "onCommand:com.netcatty.starter.greet",
+        "onView:com.netcatty.starter.panel"
+      ],
+      "permissions": {
+        "required": [
+          "commands",
+          "settings.read",
+          "menus",
+          "views"
+        ],
+        "optional": []
+      },
+      "contributes": {
+        "settings": [
+          {
+            "id": "com.netcatty.starter.greeting",
+            "label": {
+              "en": "Greeting",
+              "zh-CN": "问候语"
+            },
+            "description": "A local preference for the example command.",
+            "control": "text",
+            "scope": "application",
+            "default": "Hello, synthetic world!"
+          }
+        ],
+        "commands": [
+          {
+            "id": "com.netcatty.starter.greet",
+            "title": {
+              "en": "Starter: Read Greeting",
+              "zh-CN": "入门：读取问候语"
+            }
+          }
+        ],
+        "menus": [
+          {
+            "command": "com.netcatty.starter.greet",
+            "location": "commandPalette",
+            "group": "examples"
+          }
+        ],
+        "views": [
+          {
+            "id": "com.netcatty.starter.panel",
+            "title": {
+              "en": "Starter: Greeting Panel",
+              "zh-CN": "入门：问候面板"
+            },
+            "location": "modal",
+            "entry": "panel.html"
+          }
+        ]
+      },
+      "features": {
+        "required": [
+          "metadata.brand-icon"
+        ]
+      },
+      "icon": {
+        "kind": "package",
+        "light": "assets/logo-light.png",
+        "dark": "assets/logo-dark.png"
+      }
+    }
+  },
+  {
+    "id": "com.netcatty.hello",
+    "version": "0.1.0",
+    "name": "Hello Netcatty",
+    "description": "First-party example: greeting settings, commands and terminal providers. Build locally and import.",
+    "author": "Netcatty",
+    "repository": "binaricat/Netcatty",
+    "commit": "4336f8fd53a05a48d6bbc9ad3ce0ca88b121862f",
+    "license": "GPL-3.0-or-later",
+    "readme": "examples/plugins/hello-netcatty/README.md",
+    "manifest": {
+      "$schema": "../../../packages/plugin-contract/schema/plugin-contract.schema.json",
+      "manifestVersion": 1,
+      "id": "com.netcatty.hello",
+      "name": "hello-netcatty",
+      "displayName": {
+        "en": "Hello Netcatty",
+        "zh-CN": "你好，Netcatty"
+      },
+      "description": "Minimal plugin contract and SDK example.",
+      "version": "0.1.0",
+      "publisher": "netcatty",
+      "license": "GPL-3.0-or-later",
+      "engines": {
+        "netcatty": ">=0.0.0",
+        "api": ">=0.1.0-internal <0.2.0"
+      },
+      "main": {
+        "browser": "dist/index.js"
+      },
+      "activationEvents": [
+        "onCommand:com.netcatty.hello.sayHello",
+        "onProvider:com.netcatty.hello.completion",
+        "onProvider:com.netcatty.hello.decoration",
+        "onProvider:com.netcatty.hello.theme"
+      ],
+      "permissions": {
+        "required": [
+          "commands",
+          "settings.read",
+          "menus",
+          "provider.terminal",
+          "terminal.complete",
+          "terminal.output",
+          "terminal.decorate"
+        ],
+        "optional": []
+      },
+      "contributes": {
+        "settings": [
+          {
+            "id": "com.netcatty.hello.greeting",
+            "label": "Greeting",
+            "description": "Text used by the example command.",
+            "control": "text",
+            "scope": "application",
+            "default": "Hello from Netcatty"
+          }
+        ],
+        "commands": [
+          {
+            "id": "com.netcatty.hello.sayHello",
+            "title": "Say Hello",
+            "category": "Examples"
+          }
+        ],
+        "menus": [
+          {
+            "command": "com.netcatty.hello.sayHello",
+            "location": "commandPalette",
+            "group": "examples",
+            "order": 10
+          }
+        ],
+        "providers": [
+          {
+            "id": "com.netcatty.hello.completion",
+            "label": "Hello completion",
+            "description": "Suggests the example hello command.",
+            "kind": "terminal.completion"
+          },
+          {
+            "id": "com.netcatty.hello.decoration",
+            "label": "Hello decoration",
+            "description": "Highlights the example greeting in terminal output.",
+            "kind": "terminal.decoration"
+          },
+          {
+            "id": "com.netcatty.hello.theme",
+            "label": "Hello theme",
+            "description": "Adds a subtle cursor color to the example terminal theme.",
+            "kind": "terminal.theme"
+          }
+        ]
+      }
+    }
+  }
+]

electron/plugins/fixtures/static-distribution/delivery.json

@@ -0,0 +1,48 @@
+{
+  "builderSha256": "57199cc6a5d30f5f356adb072d51de9e2283dac6e26c647a4404e4c2261c4a70",
+  "catalogSha256": "47e967516437996e00eac8fbe97699baa72439ba1bf7ae791731e4964bb13774",
+  "indexSha256": "af2e953e3c631b36a0e712806d0dcfb0a058fd02f2051025eddded8cc115d461",
+  "plugins": [
+    {
+      "artifact": null,
+      "avatar": null,
+      "commit": "f4a6b205adca486d4e9cda0270e13a9ff0afd7be",
+      "iconDark": {
+        "path": "/assets/7a897a67ae6b652339c77a113d1c759919776fead82d2eefd0238d3c05ba87fe.png",
+        "sha256": "7a897a67ae6b652339c77a113d1c759919776fead82d2eefd0238d3c05ba87fe",
+        "size": 873
+      },
+      "iconLight": {
+        "path": "/assets/ec7bcd5e470ee3d3d9f7f77d120a4de7496a9c0ba984094f84e560d240bea947.png",
+        "sha256": "ec7bcd5e470ee3d3d9f7f77d120a4de7496a9c0ba984094f84e560d240bea947",
+        "size": 873
+      },
+      "id": "com.netcatty.starter",
+      "readme": {
+        "path": "/assets/d685ec68558c81705f03195ca35a0a62ea6ec75d8837d5ddb5b5a970890aae6e.md",
+        "sha256": "d685ec68558c81705f03195ca35a0a62ea6ec75d8837d5ddb5b5a970890aae6e",
+        "size": 2050
+      },
+      "repository": "binaricat/Netcatty",
+      "version": "0.1.2"
+    },
+    {
+      "artifact": null,
+      "avatar": null,
+      "commit": "4336f8fd53a05a48d6bbc9ad3ce0ca88b121862f",
+      "iconDark": null,
+      "iconLight": null,
+      "id": "com.netcatty.hello",
+      "readme": {
+        "path": "/assets/1692573445e3688b4fe3612282becc086b191a034c0609deeaaebf615627c209.md",
+        "sha256": "1692573445e3688b4fe3612282becc086b191a034c0609deeaaebf615627c209",
+        "size": 2951
+      },
+      "repository": "binaricat/Netcatty",
+      "version": "0.1.0"
+    }
+  ],
+  "registryCommit": "32578ae27ff86f0151511478d698a1cdc12fb2e0",
+  "schemaVersion": 1,
+  "sourceLockSha256": "753711c1860ff0fcc10a558182f8c868d9d06b40e5c8de5522249d0d27b139d6"
+}

electron/plugins/fixtures/static-distribution/index.json

@@ -0,0 +1,218 @@
+{
+  "schemaVersion": 1,
+  "plugins": [
+    {
+      "id": "com.netcatty.starter",
+      "current": "0.1.2",
+      "versions": [
+        {
+          "entry": {
+            "id": "com.netcatty.starter",
+            "version": "0.1.2",
+            "name": "Plugin Starter",
+            "description": "First-party greeting panel, local settings and commands, without terminal or secret access.",
+            "author": "Netcatty",
+            "repository": "binaricat/Netcatty",
+            "commit": "f4a6b205adca486d4e9cda0270e13a9ff0afd7be",
+            "license": "GPL-3.0-or-later",
+            "readme": "examples/plugins/starter-netcatty/README.md",
+            "manifest": {
+              "manifestVersion": 1,
+              "id": "com.netcatty.starter",
+              "name": "starter-netcatty",
+              "displayName": {
+                "en": "Plugin Starter",
+                "zh-CN": "插件入门"
+              },
+              "description": "First-party settings and command example. No terminal, network, filesystem or secret access.",
+              "version": "0.1.2",
+              "publisher": "netcatty",
+              "license": "GPL-3.0-or-later",
+              "engines": {
+                "netcatty": ">=0.0.0",
+                "api": ">=0.1.0-internal.1 <0.2.0"
+              },
+              "main": {
+                "browser": "dist/index.js"
+              },
+              "activationEvents": [
+                "onCommand:com.netcatty.starter.greet",
+                "onView:com.netcatty.starter.panel"
+              ],
+              "permissions": {
+                "required": [
+                  "commands",
+                  "settings.read",
+                  "menus",
+                  "views"
+                ],
+                "optional": []
+              },
+              "contributes": {
+                "settings": [
+                  {
+                    "id": "com.netcatty.starter.greeting",
+                    "label": {
+                      "en": "Greeting",
+                      "zh-CN": "问候语"
+                    },
+                    "description": "A local preference for the example command.",
+                    "control": "text",
+                    "scope": "application",
+                    "default": "Hello, synthetic world!"
+                  }
+                ],
+                "commands": [
+                  {
+                    "id": "com.netcatty.starter.greet",
+                    "title": {
+                      "en": "Starter: Read Greeting",
+                      "zh-CN": "入门：读取问候语"
+                    }
+                  }
+                ],
+                "menus": [
+                  {
+                    "command": "com.netcatty.starter.greet",
+                    "location": "commandPalette",
+                    "group": "examples"
+                  }
+                ],
+                "views": [
+                  {
+                    "id": "com.netcatty.starter.panel",
+                    "title": {
+                      "en": "Starter: Greeting Panel",
+                      "zh-CN": "入门：问候面板"
+                    },
+                    "location": "modal",
+                    "entry": "panel.html"
+                  }
+                ]
+              },
+              "features": {
+                "required": [
+                  "metadata.brand-icon"
+                ]
+              },
+              "icon": {
+                "kind": "package",
+                "light": "assets/logo-light.png",
+                "dark": "assets/logo-dark.png"
+              }
+            }
+          },
+          "distribution": "source-only",
+          "withdrawal": null
+        }
+      ]
+    },
+    {
+      "id": "com.netcatty.hello",
+      "current": "0.1.0",
+      "versions": [
+        {
+          "entry": {
+            "id": "com.netcatty.hello",
+            "version": "0.1.0",
+            "name": "Hello Netcatty",
+            "description": "First-party example: greeting settings, commands and terminal providers. Build locally and import.",
+            "author": "Netcatty",
+            "repository": "binaricat/Netcatty",
+            "commit": "4336f8fd53a05a48d6bbc9ad3ce0ca88b121862f",
+            "license": "GPL-3.0-or-later",
+            "readme": "examples/plugins/hello-netcatty/README.md",
+            "manifest": {
+              "$schema": "../../../packages/plugin-contract/schema/plugin-contract.schema.json",
+              "manifestVersion": 1,
+              "id": "com.netcatty.hello",
+              "name": "hello-netcatty",
+              "displayName": {
+                "en": "Hello Netcatty",
+                "zh-CN": "你好，Netcatty"
+              },
+              "description": "Minimal plugin contract and SDK example.",
+              "version": "0.1.0",
+              "publisher": "netcatty",
+              "license": "GPL-3.0-or-later",
+              "engines": {
+                "netcatty": ">=0.0.0",
+                "api": ">=0.1.0-internal <0.2.0"
+              },
+              "main": {
+                "browser": "dist/index.js"
+              },
+              "activationEvents": [
+                "onCommand:com.netcatty.hello.sayHello",
+                "onProvider:com.netcatty.hello.completion",
+                "onProvider:com.netcatty.hello.decoration",
+                "onProvider:com.netcatty.hello.theme"
+              ],
+              "permissions": {
+                "required": [
+                  "commands",
+                  "settings.read",
+                  "menus",
+                  "provider.terminal",
+                  "terminal.complete",
+                  "terminal.output",
+                  "terminal.decorate"
+                ],
+                "optional": []
+              },
+              "contributes": {
+                "settings": [
+                  {
+                    "id": "com.netcatty.hello.greeting",
+                    "label": "Greeting",
+                    "description": "Text used by the example command.",
+                    "control": "text",
+                    "scope": "application",
+                    "default": "Hello from Netcatty"
+                  }
+                ],
+                "commands": [
+                  {
+                    "id": "com.netcatty.hello.sayHello",
+                    "title": "Say Hello",
+                    "category": "Examples"
+                  }
+                ],
+                "menus": [
+                  {
+                    "command": "com.netcatty.hello.sayHello",
+                    "location": "commandPalette",
+                    "group": "examples",
+                    "order": 10
+                  }
+                ],
+                "providers": [
+                  {
+                    "id": "com.netcatty.hello.completion",
+                    "label": "Hello completion",
+                    "description": "Suggests the example hello command.",
+                    "kind": "terminal.completion"
+                  },
+                  {
+                    "id": "com.netcatty.hello.decoration",
+                    "label": "Hello decoration",
+                    "description": "Highlights the example greeting in terminal output.",
+                    "kind": "terminal.decoration"
+                  },
+                  {
+                    "id": "com.netcatty.hello.theme",
+                    "label": "Hello theme",
+                    "description": "Adds a subtle cursor color to the example terminal theme.",
+                    "kind": "terminal.theme"
+                  }
+                ]
+              }
+            }
+          },
+          "distribution": "source-only",
+          "withdrawal": null
+        }
+      ]
+    }
+  ]
+}

electron/plugins/fixtures/static-distribution/snapshot.json

@@ -0,0 +1,20 @@
+{
+  "catalog": {
+    "path": "/snapshots/53e5189d2cb58a02826931d5d6321ad3e556b924ef80d38636dc9e66a7df8c55/catalog.json",
+    "sha256": "47e967516437996e00eac8fbe97699baa72439ba1bf7ae791731e4964bb13774",
+    "size": 5739
+  },
+  "delivery": {
+    "path": "/snapshots/53e5189d2cb58a02826931d5d6321ad3e556b924ef80d38636dc9e66a7df8c55/delivery.json",
+    "sha256": "53e5189d2cb58a02826931d5d6321ad3e556b924ef80d38636dc9e66a7df8c55",
+    "size": 1869
+  },
+  "index": {
+    "path": "/snapshots/53e5189d2cb58a02826931d5d6321ad3e556b924ef80d38636dc9e66a7df8c55/index.json",
+    "sha256": "af2e953e3c631b36a0e712806d0dcfb0a058fd02f2051025eddded8cc115d461",
+    "size": 7726
+  },
+  "registryCommit": "32578ae27ff86f0151511478d698a1cdc12fb2e0",
+  "schemaVersion": 1,
+  "snapshotId": "53e5189d2cb58a02826931d5d6321ad3e556b924ef80d38636dc9e66a7df8c55"
+}

electron/plugins/fixtures/staticDistributionFixture.cjs

@@ -0,0 +1,40 @@
+"use strict";
+const fs = require("node:fs");
+const path = require("node:path");
+const { createHash } = require("node:crypto");
+const root = path.join(__dirname, "static-distribution");
+const digest = (bytes) => createHash("sha256").update(bytes).digest("hex");
+const read = (name) => fs.readFileSync(path.join(root, name));
+const catalog = JSON.parse(read("catalog.json"));
+const delivery = JSON.parse(read("delivery.json"));
+function realFiles() {
+  const pointer = JSON.parse(read("snapshot.json"));
+  const files = new Map([["/v1/snapshot.json", read("snapshot.json")]]);
+  for (const name of ["catalog", "index", "delivery"]) files.set(pointer[name].path, read(`${name}.json`));
+  for (const name of fs.readdirSync(path.join(root, "assets"))) files.set(`/assets/${name}`, read(`assets/${name}`));
+  return files;
+}
+function makeFiles(entries = catalog, mutate = () => {}) {
+  const index = { schemaVersion: 1, plugins: entries.map((entry) => ({ id: entry.id, current: entry.version, versions: [{ entry: structuredClone(entry), distribution: "source-only", withdrawal: null }] })) };
+  const sidecar = { ...structuredClone(delivery), plugins: entries.map((entry) => ({ ...structuredClone(delivery.plugins.find((item) => item.id === entry.id) ?? delivery.plugins[0]), id: entry.id, version: entry.version, repository: entry.repository, commit: entry.commit })) };
+  mutate(index, sidecar);
+  const catalogBytes = Buffer.from(JSON.stringify(entries));
+  const indexBytes = Buffer.from(JSON.stringify(index));
+  sidecar.catalogSha256 = digest(catalogBytes); sidecar.indexSha256 = digest(indexBytes);
+  const deliveryBytes = Buffer.from(JSON.stringify(sidecar));
+  const snapshotId = digest(deliveryBytes);
+  const pointer = { schemaVersion: 1, registryCommit: sidecar.registryCommit, snapshotId };
+  const files = realFiles();
+  for (const [name, bytes] of [["catalog", catalogBytes], ["index", indexBytes], ["delivery", deliveryBytes]]) {
+    const ref = { path: `/snapshots/${snapshotId}/${name}.json`, size: bytes.length, sha256: digest(bytes) };
+    pointer[name] = ref; files.set(ref.path, bytes);
+  }
+  files.set("/v1/snapshot.json", Buffer.from(JSON.stringify(pointer)));
+  return files;
+}
+function responseFor(files, url) {
+  if (new URL(url).origin !== "https://plugins.netcatty.app") throw new Error("Unexpected upstream origin");
+  const bytes = files.get(new URL(url).pathname);
+  return bytes ? new Response(bytes) : new Response("Missing fixture", { status: 404 });
+}
+module.exports = { root, read, digest, catalog, delivery, realFiles, makeFiles, responseFor };

electron/plugins/hostService.cjs

@@ -17,7 +17,7 @@ const {
   createUtilityModuleMappings,
   normalizePluginModuleResources,
 } = require("./moduleResources.cjs");
-const { PluginCatalogService } = require("./catalogService.cjs");
+const { RegistryCatalogService } = require("./registryCatalogService.cjs");
 const { PackageStore } = require("./packageStore.cjs");
 const { createPluginPaths } = require("./paths.cjs");
 const { PluginManager } = require("./pluginManager.cjs");
@@ -369,7 +369,7 @@ function createPluginHostService(options) {
       },
     });
     return {
-      catalogService: new PluginCatalogService({ manager, fetch: options.electron.net?.fetch?.bind(options.electron.net) }),
+      catalogService: new RegistryCatalogService({ manager, fetch: options.electron.net?.fetch?.bind(options.electron.net) }),
       companionSupervisor,
       contributionIconService,
       contributionService,

electron/plugins/pluginBridge.cjs

@@ -647,14 +647,14 @@ function registerPluginBridge(ipcMain, options) {
         ? { credentialStorageAvailable: credentialResolver.isAvailable() } : {}),
     };
   });
-  handle(CHANNELS.catalog, async () => options.catalogService?.list() ?? []);
+  handle(CHANNELS.catalog, async () => options.catalogService?.list() ?? { entries: [], source: "builtin", error: "Plugin catalog unavailable" });
   handle(CHANNELS.catalogReadme, async (_manager, payload) => {
     if (!options.catalogService) throw new Error("Plugin catalog unavailable");
-    return options.catalogService.readme(payload?.id);
+    return options.catalogService.readme(payload?.id, payload?.selectionToken);
   });
   handle(CHANNELS.catalogInstall, async (_manager, payload) => {
     if (!options.catalogService) throw new Error("Plugin catalog unavailable");
-    return options.catalogService.install(payload?.id);
+    return options.catalogService.install(payload?.id, payload?.selectionToken);
   });
   handle(CHANNELS.list, async (activeManager) => activeManager.list());
   handle(CHANNELS.install, async (activeManager, payload) => activeManager.install(

electron/plugins/registryCatalogService.cjs

@@ -0,0 +1,73 @@
+"use strict";
+
+const { createHash } = require("node:crypto");
+const { PluginCatalogService, validateCatalog, MAX_CATALOG_BYTES } = require("./catalogService.cjs");
+const { REGISTRY_URL, fetchDistribution, fetchVerified, tuple } = require("./distributionSnapshot.cjs");
+const tokenFor = (entry) => createHash("sha256").update(JSON.stringify(entry)).digest("hex");
+
+function prepareSnapshot(value, resources = new Map()) {
+  const entries = structuredClone(validateCatalog(value));
+  const publicEntries = structuredClone(entries).map((entry) => ({ ...entry, selectionToken: tokenFor([entry, resources.get(tuple(entry)) ?? null]) }));
+  return { entries, publicEntries, resources: structuredClone(resources) };
+}
+
+class RegistryCatalogService extends PluginCatalogService {
+  constructor(options) {
+    super(options);
+    this.publicEntries = prepareSnapshot(this.entries).publicEntries;
+    this.resources = new Map();
+    this.source = "builtin";
+    this.error = null;
+    this.refreshing = null;
+  }
+  async refresh() {
+    if (this.refreshing) return this.refreshing;
+    this.refreshing = (async () => {
+      try {
+        // No redirects: only this exact registry endpoint can replace the catalog.
+        const distribution = await fetchDistribution(this.fetch);
+        const next = prepareSnapshot(distribution.entries, distribution.resources);
+        // Publish only after full validation, clones and every token succeeded.
+        this.entries = next.entries;
+        this.publicEntries = next.publicEntries;
+        this.resources = next.resources;
+        this.source = "registry";
+        this.error = null;
+        return true;
+      } catch (error) {
+        if (this.source === "registry") this.source = "cached";
+        this.error = String(error.message ?? error).slice(0, 1024);
+        return false;
+      }
+    })();
+    try { return await this.refreshing; } finally { this.refreshing = null; }
+  }
+  async list() {
+    await this.refresh();
+    return {
+      entries: structuredClone(this.publicEntries),
+      source: this.source,
+      error: this.error,
+    };
+  }
+  selected(id, token) {
+    const entry = this.get(id);
+    if (typeof token !== "string" || token !== this.publicEntries.find((item) => item.id === id)?.selectionToken) {
+      throw new Error("Catalog entry changed. Refresh and review this version before continuing.");
+    }
+    return entry;
+  }
+  async readme(id, token) {
+    const entry = this.selected(id, token);
+    const resource = this.resources.get(tuple(entry))?.readme;
+    if (!resource) throw new Error("No published README snapshot is available. Refresh the catalog or open its source link.");
+    return (await fetchVerified(resource, this.fetch)).toString("utf8");
+  }
+  async install(id, token) {
+    this.selected(id, token);
+    if (!await this.refresh()) throw new Error("Registry refresh failed. Cached catalogs are browse-only; retry when online.");
+    this.selected(id, token);
+    return super.install(id);
+  }
+}
+module.exports = { RegistryCatalogService, REGISTRY_URL, MAX_CATALOG_BYTES };

electron/plugins/registryCatalogService.test.cjs

@@ -0,0 +1,93 @@
+"use strict";
+const assert = require("node:assert/strict");
+const test = require("node:test");
+const { RegistryCatalogService, REGISTRY_URL } = require("./registryCatalogService.cjs");
+const { catalog, realFiles, makeFiles, responseFor } = require("./fixtures/staticDistributionFixture.cjs");
+
+test("registry starts at a fixed anonymous pointer and retains only complete validated snapshots", async () => {
+  let files = realFiles();
+  const service = new RegistryCatalogService({ fetch: async (url, options) => {
+    assert.equal(new URL(url).origin, "https://plugins.netcatty.app");
+    assert.equal(options.credentials, "omit"); assert.equal(options.redirect, "manual");
+    assert.equal(options.referrerPolicy, "no-referrer"); assert.ok(options.signal);
+    return responseFor(files, url);
+  } });
+  const good = await service.list();
+  assert.equal(good.source, "registry"); assert.equal(good.entries.length, 2);
+  assert.match(good.entries[0].selectionToken, /^[a-f0-9]{64}$/);
+  for (const invalid of ["{", "{}", JSON.stringify({ schemaVersion: 2 }), '{"schemaVersion":1e999}', " ".repeat(16 * 1024 + 1)]) {
+    files = realFiles(); files.set("/v1/snapshot.json", Buffer.from(invalid));
+    const cached = await service.list();
+    assert.equal(cached.source, "cached"); assert.ok(cached.error);
+    assert.deepEqual(cached.entries, good.entries);
+  }
+  files = makeFiles([]);
+  assert.deepEqual((await service.list()).entries, []);
+});
+
+test("offline first launch returns bundled source examples with no GitHub README fallback", async () => {
+  let calls = 0;
+  const service = new RegistryCatalogService({ fetch: async (url) => { calls++; assert.equal(url, REGISTRY_URL); throw new Error("offline"); }, manager: {
+    install() { assert.fail("offline must not install"); },
+  } });
+  const snapshot = await service.list();
+  assert.equal(snapshot.source, "builtin"); assert.equal(snapshot.entries.length, 2);
+  await assert.rejects(service.readme(snapshot.entries[0].id, snapshot.entries[0].selectionToken), /No published README/);
+  assert.equal(calls, 1);
+  await assert.rejects(service.install(snapshot.entries[0].id, snapshot.entries[0].selectionToken), /browse-only/);
+});
+
+test("selection binds source and delivery metadata; changes and withdrawal cannot silently install", async () => {
+  let files = realFiles(); const requests = [];
+  const service = new RegistryCatalogService({ fetch: async (url) => { requests.push(url); return responseFor(files, url); }, manager: { install() { assert.fail("source-only must not install"); } } });
+  const selected = (await service.list()).entries[0];
+  assert.match(await service.readme(selected.id, selected.selectionToken), /Starter/);
+  await assert.rejects(service.readme(selected.id, "bad"), /changed/);
+  const before = requests.length;
+  await assert.rejects(service.install(selected.id), /changed/); assert.equal(requests.length, before);
+  await assert.rejects(service.install(selected.id, selected.selectionToken), /no published package/);
+  const changed = structuredClone(catalog); changed[0].description += " changed";
+  files = makeFiles(changed);
+  await assert.rejects(service.install(selected.id, selected.selectionToken), /changed/);
+  await assert.rejects(service.readme(selected.id, selected.selectionToken), /changed/);
+  files = makeFiles([]);
+  assert.deepEqual((await service.list()).entries, []);
+  await assert.rejects(service.install(selected.id, selected.selectionToken), /curated catalog/);
+});
+
+test("concurrent list refreshes share one pointer request and complete document set", async () => {
+  let finish; const requests = []; const files = realFiles();
+  const service = new RegistryCatalogService({ fetch: async (url) => { requests.push(url); if (url === REGISTRY_URL) return new Promise((resolve) => { finish = resolve; }); return responseFor(files, url); } });
+  const first = service.list(); const second = service.list();
+  finish(responseFor(files, REGISTRY_URL));
+  assert.deepEqual(await first, await second); assert.equal(requests.length, 4);
+});
+
+test("invalid sources and unknown JSON fields cannot poison good offline snapshots", async () => {
+  let files = realFiles(); let offline = false;
+  const service = new RegistryCatalogService({ fetch: async (url) => { if (offline) throw new Error("offline"); return responseFor(files, url); } });
+  const good = await service.list();
+  let nested = null; for (let i = 0; i < 130; i++) nested = { child: nested };
+  const bad = [
+    { ...catalog[0], readme: "\t../main/README.md" }, { ...catalog[0], repository: "example/.." },
+    { ...catalog[0], unknownNestedField: nested }, { ...catalog[0], unknownField: true },
+    { ...catalog[0], readmeAsset: { url: "https://plugins.netcatty.app/a", sha256: "a".repeat(64) } },
+  ];
+  for (const entry of bad) {
+    files = makeFiles([entry]); offline = false;
+    const rejected = await service.list(); assert.equal(rejected.source, "cached"); assert.ok(rejected.error);
+    assert.deepEqual(rejected.entries, good.entries);
+    offline = true; assert.deepEqual((await service.list()).entries, good.entries);
+  }
+});
+
+test("snapshot preparation failure leaves private resources and public tokens unchanged", async () => {
+  const service = new RegistryCatalogService({ fetch: async (url) => responseFor(realFiles(), url) });
+  const good = await service.list(); const resources = service.resources;
+  const originalClone = global.structuredClone;
+  try { global.structuredClone = () => { throw new Error("synthetic clone failure"); }; assert.equal(await service.refresh(), false); }
+  finally { global.structuredClone = originalClone; }
+  assert.equal(service.resources, resources);
+  service.fetch = async () => { throw new Error("offline"); };
+  assert.deepEqual((await service.list()).entries, good.entries);
+});

electron/plugins/staticDistribution.test.cjs

@@ -0,0 +1,106 @@
+"use strict";
+const assert = require("node:assert/strict");
+const test = require("node:test");
+const { assertDownloadUrl, fetchBounded, validateCatalog } = require("./catalogService.cjs");
+const { RegistryCatalogService, REGISTRY_URL } = require("./registryCatalogService.cjs");
+const { fetchVerified, assertAsset } = require("./distributionSnapshot.cjs");
+const { read, digest, catalog, delivery, realFiles, makeFiles, responseFor } = require("./fixtures/staticDistributionFixture.cjs");
+
+test("exact registry PR3 bootstrap hashes and all README/icon assets verify without GitHub requests", async () => {
+  assert.equal(digest(read("snapshot.json")), "2878885057a01585e34897c226bcfd81615345d843ea94297980de7e397b4617");
+  assert.equal(digest(read("delivery.json")), "53e5189d2cb58a02826931d5d6321ad3e556b924ef80d38636dc9e66a7df8c55");
+  const requests = []; const files = realFiles();
+  const fetch = async (url, options) => {
+    requests.push(url); assert.equal(new URL(url).origin, "https://plugins.netcatty.app");
+    assert.equal(options.credentials, "omit"); assert.equal(options.redirect, "manual");
+    return responseFor(files, url);
+  };
+  const service = new RegistryCatalogService({ fetch });
+  const snapshot = await service.list();
+  assert.equal(snapshot.error, null); assert.equal(snapshot.source, "registry");
+  assert.equal(requests.length, 4); assert.equal(requests[0], REGISTRY_URL);
+  for (const entry of snapshot.entries) {
+    const resource = delivery.plugins.find((item) => item.id === entry.id);
+    assert.equal(await service.readme(entry.id, entry.selectionToken), read(resource.readme.path.slice(1)).toString());
+    for (const icon of [resource.iconLight, resource.iconDark]) if (icon) {
+      assertAsset(icon, ["png", "webp"]);
+      const bytes = await fetchVerified(icon, fetch);
+      assert.equal(bytes.length, icon.size); assert.equal(digest(bytes), icon.sha256);
+    }
+    assert.equal(entry.artifact, undefined);
+    assert.equal(resource.avatar, null); assert.equal(resource.artifact, null);
+  }
+  assert.ok(requests.every((url) => !/github/u.test(url)));
+});
+
+test("GitHub, tracking and noncanonical URLs are rejected before any upstream request", async () => {
+  for (const url of [
+    "https://api.github.com/repos/a/b", "https://raw.githubusercontent.com/a/b/main/README.md",
+    "https://avatars.githubusercontent.com/u/1", "https://github.com/a/b/releases/download/v1/a.ncpkg",
+    "https://release-assets.githubusercontent.com/a", "https://objects.githubusercontent.com/a",
+    "https://plugins.netcatty.app.attacker.invalid/a", "https://plugins.netcatty.app@attacker.invalid/a",
+    "http://plugins.netcatty.app/a", "https://plugins.netcatty.app/a?track=1", "https://plugins.netcatty.app/a#fragment",
+    "https://plugins.netcatty.app/a/../b", "https://plugins.netcatty.app/%2e%2e/b", "https://plugins.netcatty.app/\ta",
+  ]) {
+    assert.throws(() => assertDownloadUrl(url));
+    assert.throws(() => validateCatalog([{ ...catalog[0], artifact: { url, sha256: "a".repeat(64) } }]));
+    await assert.rejects(fetchBounded(url, 1024, () => assert.fail("invalid source must not be requested")));
+  }
+});
+
+test("official responses never redirect to GitHub or another official path", async () => {
+  for (const location of ["https://github.com/a", "https://raw.githubusercontent.com/a/b/main/catalog.json", "https://plugins.netcatty.app/another.json"]) {
+    const requests = [];
+    await assert.rejects(fetchBounded(REGISTRY_URL, 1024, async (url) => {
+      requests.push(url); return new Response(null, { status: 302, headers: { location } });
+    }), /redirects/);
+    assert.deepEqual(requests, [REGISTRY_URL]);
+  }
+});
+
+test("cross-document mismatches, withdrawn versions and unsupported assets preserve the complete good cache", async () => {
+  let files = realFiles(); const service = new RegistryCatalogService({ fetch: async (url) => responseFor(files, url) });
+  const good = await service.list(); const goodResources = service.resources;
+  const mutations = [
+    (index, sidecar) => { sidecar.registryCommit = "a".repeat(40); },
+    (index, sidecar) => { sidecar.plugins[0].commit = "a".repeat(40); },
+    (index, sidecar) => { sidecar.plugins.push(sidecar.plugins[0]); },
+    (index, sidecar) => { sidecar.plugins.pop(); },
+    (index, sidecar) => { sidecar.plugins[0].readme.path = "https://raw.githubusercontent.com/a/b/main/README.md"; },
+    (index, sidecar) => { sidecar.plugins[0].readme.path = `/assets/${sidecar.plugins[0].readme.sha256}.png`; },
+    (index, sidecar) => { sidecar.plugins[0].iconLight.path = `/assets/${sidecar.plugins[0].iconLight.sha256}.md`; },
+    (index, sidecar) => { sidecar.plugins[0].avatar = { path: "/assets/avatar.png" }; },
+    (index, sidecar) => { sidecar.plugins[0].artifact = { path: "/assets/package.ncpkg" }; },
+    (index) => { index.plugins[0].versions[0].withdrawal = { at: "2026-10-26T00:00:00Z", reason: "synthetic withdrawal", advisory: "https://github.com/example/advisory" }; },
+    (index) => { index.plugins[0].versions[0].entry.description += " mismatch"; },
+    (index) => { index.plugins[0].current = "9.0.0"; },
+    (index) => { index.plugins.push(index.plugins[0]); },
+    (index, sidecar) => { sidecar.unknown = true; },
+  ];
+  for (const mutate of mutations) {
+    files = makeFiles(catalog, mutate);
+    // Preserve the pointer's trusted registry identity when testing delivery mismatch.
+    const pointer = JSON.parse(files.get("/v1/snapshot.json")); pointer.registryCommit = delivery.registryCommit;
+    files.set("/v1/snapshot.json", Buffer.from(JSON.stringify(pointer)));
+    const rejected = await service.list();
+    assert.equal(rejected.source, "cached"); assert.ok(rejected.error);
+    assert.deepEqual(rejected.entries, good.entries); assert.equal(service.resources, goodResources);
+  }
+});
+
+test("pointer/document/resource byte mismatches and partial availability never publish partial state", async () => {
+  let files = realFiles(); const service = new RegistryCatalogService({ fetch: async (url) => responseFor(files, url) });
+  const good = await service.list();
+  const pointer = JSON.parse(read("snapshot.json"));
+  for (const name of ["catalog", "index", "delivery"]) {
+    files = realFiles(); files.set(pointer[name].path, Buffer.from("{}"));
+    const rejected = await service.list(); assert.equal(rejected.source, "cached"); assert.deepEqual(rejected.entries, good.entries);
+    files = realFiles(); files.delete(pointer[name].path);
+    assert.deepEqual((await service.list()).entries, good.entries);
+  }
+  files = realFiles(); const altered = structuredClone(pointer); altered.catalog.path = "/catalog.json";
+  files.set("/v1/snapshot.json", Buffer.from(JSON.stringify(altered)));
+  assert.match((await service.list()).error, /resource reference/);
+  files = realFiles(); files.set(delivery.plugins[0].readme.path, Buffer.from("x".repeat(delivery.plugins[0].readme.size)));
+  await assert.rejects(service.readme(good.entries[0].id, good.entries[0].selectionToken), /SHA-256 mismatch/);
+});

electron/preload/api.cjs

@@ -100,8 +100,8 @@ function createPreloadApi(ctx) {
     return {
   getPluginRuntimeStatus: () => ipcRenderer.invoke("netcatty:plugins:status"),
   listPluginCatalog: () => ipcRenderer.invoke("netcatty:plugins:catalog"),
-  getPluginCatalogReadme: (id) => ipcRenderer.invoke("netcatty:plugins:catalog-readme", { id }),
-  installCatalogPlugin: (id) => ipcRenderer.invoke("netcatty:plugins:catalog-install", { id }),
+  getPluginCatalogReadme: (id, selectionToken) => ipcRenderer.invoke("netcatty:plugins:catalog-readme", { id, selectionToken }),
+  installCatalogPlugin: (id, selectionToken) => ipcRenderer.invoke("netcatty:plugins:catalog-install", { id, selectionToken }),
   listPlugins: () => ipcRenderer.invoke("netcatty:plugins:list"),
   installPluginPackage: (archivePath, options) => ipcRenderer.invoke("netcatty:plugins:install", {
     archivePath,

global.d.ts

@@ -334,7 +334,14 @@ declare global {
     credentialStorageAvailable?: boolean;
   }
 
+  interface NetcattyPluginCatalogSnapshot {
+    entries: NetcattyPluginCatalogEntry[];
+    source: "registry" | "cached" | "builtin";
+    error: string | null;
+  }
+
   interface NetcattyPluginCatalogEntry {
+    selectionToken?: string;
     id: string;
     version: string;
     name: string;
@@ -425,9 +432,9 @@ declare global {
 
   interface NetcattyBridge {
     getPluginRuntimeStatus?(): Promise<NetcattyPluginRuntimeStatus>;
-    listPluginCatalog?(): Promise<NetcattyPluginCatalogEntry[]>;
-    getPluginCatalogReadme?(id: string): Promise<string>;
-    installCatalogPlugin?(id: string): Promise<NetcattyInstalledPlugin>;
+    listPluginCatalog?(): Promise<NetcattyPluginCatalogSnapshot>;
+    getPluginCatalogReadme?(id: string, selectionToken?: string): Promise<string>;
+    installCatalogPlugin?(id: string, selectionToken?: string): Promise<NetcattyInstalledPlugin>;
     listPlugins?(): Promise<NetcattyInstalledPlugin[]>;
     installPluginPackage?(archivePath: string, options?: { enable?: boolean }): Promise<NetcattyInstalledPlugin>;
     setPluginEnabled?(pluginId: string, enabled: boolean): Promise<NetcattyInstalledPlugin>;