feat(cli): add /update slash command to CLI and TUI (#23854)

* feat: add /update slash command to CLI and TUI

* test(cli): add Python tests for /update slash command

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(cli): address Copilot review for /update slash command

Route classic CLI /update through prompt_toolkit modal confirmation and
defer relaunch to the main-thread cleanup path after app.exit(). Tighten
Y/n semantics, add Python wrapper and catalog coverage tests, and assert
/update stays visible in the TUI command catalog.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(cli): address review feedback on /update command

- Replace raw input() with _prompt_text_input_modal in _handle_update_command
  to avoid EOF/hang/keystroke-leak races with prompt_toolkit's stdin ownership
- Fix confirmation logic: only proceed on recognized affirmative aliases
  (y/yes/1/ok); cancel on everything else including empty string, typos,
  and unrecognized input — matches all other [Y/n] prompts in the codebase
- Route relaunch through main-thread shutdown path: set _pending_relaunch
  and return False from process_command so process_loop triggers app.exit();
  run() then calls relaunch() after prompt_toolkit has restored terminal modes
  and after cleanup — safe on both POSIX (execvp) and Windows (subprocess+exit)
- Fix misleading docstring in test_update_command.py: the Vitest only covers
  the TypeScript slash handler that emits code 42, not the Python wrapper
  branch that acts on it
- Rewrite tests to use SimpleNamespace pattern (like test_destructive_slash_confirm)
  so _prompt_text_input_modal can be stubbed directly
- Add Python test for _launch_tui exit-code-42 → relaunch branch in main.py

Agent-Logs-Url: https://github.com/NousResearch/hermes-agent/sessions/f6da68cf-e7b1-4b7a-aed6-3d4b0f523bdb

Co-authored-by: austinpickett <260188+austinpickett@users.noreply.github.com>

* fix(cli): polish test fixtures for /update command

- Remove unused _prompt_text_input from SimpleNamespace stub
- Use pytest.fail sentinel in managed-install guard test to catch unexpected modal invocations

Agent-Logs-Url: https://github.com/NousResearch/hermes-agent/sessions/f6da68cf-e7b1-4b7a-aed6-3d4b0f523bdb

Co-authored-by: austinpickett <260188+austinpickett@users.noreply.github.com>

* chore: re-trigger CI after Copilot review fixes

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: austinpickett <260188+austinpickett@users.noreply.github.com>

ui-tui/src/app/interfaces.ts

@@ -277,6 +277,7 @@ export interface SlashHandlerContext {
   session: {
     closeSession: (targetSid?: null | string) => Promise<unknown>
     die: () => void
+    dieWithCode: (code: number) => void
     guardBusySessionSwitch: (what?: string) => boolean
     newSession: (msg?: string, title?: string) => void
     resetVisibleHistory: (info?: null | SessionInfo) => void

ui-tui/src/app/slash/commands/core.ts

@@ -92,6 +92,17 @@ export const coreCommands: SlashCommand[] = [
     run: (_arg, ctx) => ctx.session.die()
   },
 
+  {
+    help: 'update Hermes Agent to the latest version (exits TUI)',
+    name: 'update',
+    run: (_arg, ctx) => {
+      ctx.transcript.sys('exiting TUI to run update...')
+      // Exit code 42 signals the Python wrapper to exec `hermes update`.
+      // Use dieWithCode for proper cleanup (gateway kill + Ink unmount).
+      setTimeout(() => ctx.session.dieWithCode(42), 100)
+    }
+  },
+
   {
     aliases: ['scroll'],
     help: 'toggle mouse/wheel tracking [on|off|toggle]',

ui-tui/src/app/useMainApp.ts

@@ -377,6 +377,12 @@ export function useMainApp(gw: GatewayClient) {
     process.exit(0)
   }, [exit, gw])
 
+  const dieWithCode = useCallback((code: number) => {
+    gw.kill()
+    exit()
+    process.exit(code)
+  }, [exit, gw])
+
   const session = useSessionLifecycle({
     colsRef,
     composerActions,
@@ -643,6 +649,7 @@ export function useMainApp(gw: GatewayClient) {
         session: {
           closeSession: session.closeSession,
           die,
+          dieWithCode,
           guardBusySessionSwitch: session.guardBusySessionSwitch,
           newSession: session.newSession,
           resetVisibleHistory: session.resetVisibleHistory,