fix(mcp): allow ] inside RHEL prompt \W segment

The final ] before $ or # stays the delimiter, so a basename
like My [Project] still clears the idle-prompt readiness gate.

Co-authored-by: 陈大猫 <binaricat@users.noreply.github.com>

electron/bridges/ai/shellUtils.cjs

@@ -61,10 +61,13 @@ const POWERSHELL_PROMPT_PATTERN = /^PS(?:\s+\S.*)?>$/;
 // PowerShell's `PS C:\...>` (handled by POWERSHELL_PROMPT_PATTERN first).
 const CMD_PROMPT_PATTERN = /^[A-Za-z]:(?:\\[^<>"|]*)?>$/;
 
-// Classic `user@host:...$` / `user@host:...#` login prompt (bash/zsh in WSL,
-// remote Linux, etc.). Intentionally narrow so custom / fish prompts do not
-// flip a Windows DefaultShell soft hint.
-const POSIX_PROMPT_PATTERN = /^[^\s@]+@[^\s:]+(?::[^\n\r]*)?[#$]$/;
+// Default login prompts, kept narrow so custom / fish / starship prompts do
+// not flip a Windows DefaultShell soft hint:
+//   - bash/zsh `user@host[:path][#$]` (colon before the path; `root@host ~#` stays rejected)
+//   - RHEL-family `[\u@\h \W]\$` -> `[user@host path][#$]`, or `[user@host][#$]`
+//     with no path. `\W` may contain whitespace or `]` (`[user@host My [Project]]$`);
+//     the final `]` before `$`/`#` is the delimiter.
+const POSIX_PROMPT_PATTERN = /^(?:[^\s@]+@[^\s:]+(?::[^\n\r]*)?|\[[^\s@\]]+@[^\s\]:]+(?:\s+[^\n\r]+)?\])[#$]$/;
 
 function isDefaultPowerShellPromptLine(line) {
   return POWERSHELL_PROMPT_PATTERN.test(String(line || ""));
@@ -149,7 +152,7 @@ function trackSessionIdlePrompt(session, chunk) {
 // Return `session.lastIdlePrompt` only if the PTY's recent rolling tail
 // still ends with it. The cached prompt is updated only when
 // extractTrailingIdlePrompt recognizes a known shape (PowerShell, cmd.exe,
-// or `user@host[:path][#$]`); a remote shell switch into another shell, an
+// `user@host[:path][#$]`, or RHEL `[user@host path][#$]`); 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`
 // would then keep using to coerce future commands into a PowerShell

electron/bridges/ai/shellUtils.test.cjs

@@ -133,14 +133,50 @@ test("isDefaultCmdPromptLine matches drive-letter cmd prompts only", () => {
 
 test("isDefaultPosixPromptLine matches classic user@host prompts", () => {
   assert.equal(isDefaultPosixPromptLine("alice@host:~$"), true);
+  assert.equal(isDefaultPosixPromptLine("user@host:~$"), true);
   assert.equal(isDefaultPosixPromptLine("alice@wsl:/mnt/c$"), true);
   assert.equal(isDefaultPosixPromptLine("root@box:/#"), true);
+  assert.equal(isDefaultPosixPromptLine("[opc@instance-20260905-1821 ~]$"), true);
+  assert.equal(isDefaultPosixPromptLine("[opc@instance-20260905-1821 ~]$ "), true);
+  assert.equal(isDefaultPosixPromptLine("[root@host ~]#"), true);
+  assert.equal(isDefaultPosixPromptLine("[user@host]$"), true);
+  assert.equal(isDefaultPosixPromptLine("[user@host My Project]$"), true);
+  assert.equal(isDefaultPosixPromptLine("[user@host My Project]$ "), true);
+  assert.equal(isDefaultPosixPromptLine("[user@host My [Project]]$"), true);
+  assert.equal(isDefaultPosixPromptLine("[user@host My [Project]]$ "), true);
   assert.equal(isDefaultPosixPromptLine("root@host ~#"), false);
   assert.equal(isDefaultPosixPromptLine("PS C:\\Users\\alice>"), false);
   assert.equal(isDefaultPosixPromptLine("C:\\Users\\alice>"), false);
   assert.equal(isDefaultPosixPromptLine(""), false);
 });
 
+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.
+  assert.equal(
+    extractTrailingIdlePrompt("[opc@instance-20260905-1821 ~]$ "),
+    "[opc@instance-20260905-1821 ~]$ ",
+  );
+  assert.equal(
+    extractTrailingIdlePrompt("Last login: Fri Oct 24\r\n[root@host ~]#"),
+    "[root@host ~]#",
+  );
+  assert.equal(
+    extractTrailingIdlePrompt("welcome\r\nuser@host:~$ "),
+    "user@host:~$ ",
+  );
+  assert.equal(
+    extractTrailingIdlePrompt("welcome\r\n[user@host My Project]$ "),
+    "[user@host My Project]$ ",
+  );
+  assert.equal(
+    extractTrailingIdlePrompt("welcome\r\n[user@host My [Project]]$ "),
+    "[user@host My [Project]]$ ",
+  );
+  // Unbracketed space form is still not a recognized default prompt.
+  assert.equal(extractTrailingIdlePrompt("welcome\r\nroot@host ~#"), "");
+});
+
 test("isPlausibleCliVersionOutput rejects stack traces and file URLs", () => {
   assert.equal(isPlausibleCliVersionOutput("2.1.123 (Claude Code)"), true);
   assert.equal(isPlausibleCliVersionOutput("codex-cli 0.125.0"), true);
@@ -674,6 +710,35 @@ test("getFreshIdlePrompt returns empty string when the session has no cached pro
   );
 });
 
+test("trackSessionIdlePrompt and getFreshIdlePrompt accept an Oracle/RHEL bracketed bash prompt", () => {
+  const session = {};
+  trackSessionIdlePrompt(session, "Last login...\r\n[opc@instance-20260905-1821 ~]$ ");
+  assert.equal(session.lastIdlePrompt, "[opc@instance-20260905-1821 ~]$ ");
+  assert.equal(getFreshIdlePrompt(session), "[opc@instance-20260905-1821 ~]$ ");
+
+  const rootSession = {};
+  trackSessionIdlePrompt(rootSession, "[root@host ~]#");
+  assert.equal(getFreshIdlePrompt(rootSession), "[root@host ~]#");
+
+  const classic = {};
+  trackSessionIdlePrompt(classic, "user@host:~$ ");
+  assert.equal(getFreshIdlePrompt(classic), "user@host:~$ ");
+
+  const unbracketed = {};
+  assert.equal(trackSessionIdlePrompt(unbracketed, "root@host ~#"), "");
+  assert.equal(getFreshIdlePrompt(unbracketed), "");
+
+  const spacedPath = {};
+  trackSessionIdlePrompt(spacedPath, "Last login...\r\n[user@host My Project]$ ");
+  assert.equal(spacedPath.lastIdlePrompt, "[user@host My Project]$ ");
+  assert.equal(getFreshIdlePrompt(spacedPath), "[user@host My Project]$ ");
+
+  const bracketedPath = {};
+  trackSessionIdlePrompt(bracketedPath, "Last login...\r\n[user@host My [Project]]$ ");
+  assert.equal(bracketedPath.lastIdlePrompt, "[user@host My [Project]]$ ");
+  assert.equal(getFreshIdlePrompt(bracketedPath), "[user@host My [Project]]$ ");
+});
+
 test("getFreshIdlePrompt and trackSessionIdlePrompt round-trip through a real PTY-like flow", () => {
   // (1) Remote PowerShell prompt arrives — lastIdlePrompt is captured.
   const session = {};