fix(mcp): recognize Powerlevel10k ❯ idle prompts

Powerlevel10k paints idle prompts like `~ ❯` / `alice@host ~/src ❯`.
The POSIX idle whitelist never matched Unicode ❯, so MCP terminal_execute
stayed SHELL_NOT_READY while bash `$` worked. Accept common p10k ❯ lines
and still reject pending input and bare ❯.

Fixes #4075

electron/bridges/ai/shellUtils.cjs

@@ -99,6 +99,15 @@ const OH_MY_ZSH_YS_HOST_LINE_PATTERN = /^#\s+[^\s@]+\s+@\s+[^\s]+(?:\s+[^\n\r]+)
 // within the path so partially entered commands do not count as idle prompts.
 const ALPINE_PROMPT_PATTERN = /^[A-Za-z0-9_][A-Za-z0-9_.-]*:(?:~(?:\/[^#$\n\r]*)?|\/[^#$\n\r]*)[#$]$/;
 
+// Powerlevel10k / similar Unicode prompt-ending ❯ (U+276F). Common idle forms:
+// `~ ❯`, `~/path ❯`, `/tmp ❯`, short-dir `proj ❯`, optional `user@host `
+// prefix (`alice@host ~ ❯`). Require a non-empty prefix and whitespace before
+// ❯ so pending input (`~ ❯ echo READY`, `❯ vim`) cannot match. Bare `❯` alone
+// is intentionally rejected — too ambiguous without a path/host prefix
+// (same rationale as bare `$`/`#`). Do not attempt two-line bare-❯ here.
+const POWERLEVEL10K_PROMPT_PATTERN =
+  /^(?:[^\s@]+@[^\s:]+\s+)?[^\s❯][^❯\r\n]*\s+❯$/;
+
 function isDefaultPowerShellPromptLine(line) {
   return POWERSHELL_PROMPT_PATTERN.test(String(line || ""));
 }
@@ -117,7 +126,8 @@ function isDefaultPosixPromptLine(line) {
     POSIX_PROMPT_PATTERN.test(withoutEnvPrefix) ||
     PAREN_POSIX_PROMPT_PATTERN.test(withoutEnvPrefix) ||
     ALPINE_PROMPT_PATTERN.test(withoutEnvPrefix) ||
-    ZSH_PROMPT_PATTERN.test(withoutEnvPrefix)
+    ZSH_PROMPT_PATTERN.test(withoutEnvPrefix) ||
+    POWERLEVEL10K_PROMPT_PATTERN.test(withoutEnvPrefix)
   );
 }
 
@@ -234,8 +244,8 @@ function trackSessionIdlePrompt(session, chunk) {
 // still ends with it. The cached prompt is updated only when
 // extractTrailingIdlePrompt recognizes a known shape (PowerShell, cmd.exe,
 // `user@host[:path][#$]`, two-line classic `user@host[:path]` or Oh My Zsh
-// `ys` (`# user @ host ...`) + `$`/`#`, RHEL `[user@host path][#$]`, or
-// Alpine `host:path[#$]`);
+// `ys` (`# user @ host ...`) + `$`/`#`, RHEL `[user@host path][#$]`,
+// Alpine `host:path[#$]`, or Powerlevel10k-style `... ❯`);
 // a remote shell switch into another shell, an oh-my-posh / starship / custom
 // PS1, or any unrecognized prompt would
 // otherwise leave a stale value behind, which `resolveEffectiveShellKind`

electron/bridges/ai/shellUtils.test.cjs

@@ -261,6 +261,70 @@ test("extracts an Alpine idle prompt while preserving its trailing whitespace",
   assert.equal(extractTrailingIdlePrompt("localhost:~# \r\n"), "");
 });
 
+test("isDefaultPosixPromptLine matches Powerlevel10k ❯ idle prompts", () => {
+  for (const prompt of [
+    "~ ❯",
+    "~ ❯ ",
+    "~/proj ❯",
+    "~/git/Netcatty ❯ ",
+    "/tmp ❯",
+    "proj ❯",
+    "alice@host ~ ❯",
+    "alice@host ~/src ❯ ",
+    "(venv) ~ ❯ ",
+    "(venv) alice@host ~ ❯",
+  ]) {
+    assert.equal(isDefaultPosixPromptLine(prompt), true, prompt);
+  }
+});
+
+test("Powerlevel10k ❯ recognition rejects pending input and bare ❯", () => {
+  for (const line of [
+    "❯",
+    "❯ ",
+    "❯ vim",
+    "~ ❯ echo READY",
+    "~ ❯echo",
+    "alice@host ~ ❯ ls",
+    "proj ❯ vim",
+    "(venv) ~ ❯ echo hi",
+    // Must not treat a lone marker as idle (same rationale as bare $/).
+  ]) {
+    assert.equal(isDefaultPosixPromptLine(line), false, line);
+    assert.equal(extractTrailingIdlePrompt(`welcome\r\n${line}`), "", line);
+  }
+});
+
+test("extractTrailingIdlePrompt recognizes Powerlevel10k ❯ and preserves trailing space", () => {
+  assert.equal(extractTrailingIdlePrompt("welcome\r\n~ ❯"), "~ ❯");
+  assert.equal(extractTrailingIdlePrompt("welcome\r\n~ ❯ "), "~ ❯ ");
+  assert.equal(
+    extractTrailingIdlePrompt("Last login...\r\nalice@host ~/src ❯ "),
+    "alice@host ~/src ❯ ",
+  );
+  assert.equal(extractTrailingIdlePrompt("welcome\r\nproj ❯"), "proj ❯");
+  assert.equal(extractTrailingIdlePrompt("(venv) ~ ❯ "), "(venv) ~ ❯ ");
+  assert.equal(extractTrailingIdlePrompt("welcome\r\n~ ❯ echo READY"), "");
+  assert.equal(extractTrailingIdlePrompt("welcome\r\n❯ "), "");
+  assert.equal(extractTrailingIdlePrompt("welcome\r\n~ ❯\r\n"), "");
+});
+
+test("trackSessionIdlePrompt and getFreshIdlePrompt accept a Powerlevel10k ❯ prompt", () => {
+  const session = {};
+  trackSessionIdlePrompt(session, "Last login...\r\n~ ❯ ");
+  assert.equal(session.lastIdlePrompt, "~ ❯ ");
+  assert.equal(getFreshIdlePrompt(session), "~ ❯ ");
+  assert.equal(getVisibleIdlePrompt(session), "~ ❯ ");
+
+  trackSessionIdlePrompt(session, "printf busy");
+  assert.equal(getFreshIdlePrompt(session), "");
+  assert.equal(getVisibleIdlePrompt(session), "");
+
+  trackSessionIdlePrompt(session, "\r\nbusy\r\nalice@host ~/src ❯ ");
+  assert.equal(getFreshIdlePrompt(session), "alice@host ~/src ❯ ");
+  assert.equal(getVisibleIdlePrompt(session), "alice@host ~/src ❯ ");
+});
+
 test("extracts a trailing RHEL-family bracketed idle prompt", () => {
   // Oracle Linux / RHEL / CentOS / Fedora default PS1 is `[\u@\h \W]\$ `.
   // Trailing space must round-trip, same as the PowerShell prompt capture.