fix: address PR review findings for Gemini run mode + Ralph todo-config

Gemini (PR #134) blockers:
- runGemini() now unwraps the {success,data} envelope: status check reads
  .data.available, quick-start reads data.data.sessionId (was reading the raw
  shape, so the Run-Gemini button could never start a session).
- setGeminiEnvVars() now uses the socket-scoped ${this.tmux()} setenv instead of
  bare tmux — Gemini/Google auth env vars were targeting the wrong tmux server
  and silently failing on every install.

Gemini parity polish:
- gemini tab-mode badge ('gm') + .tab-mode.gemini CSS; kill-dialog label
  'Kill Tmux & Gemini'; codeman doctor dependency-registry entry; export
  isGeminiAvailable from utils barrel; COLORTERM=truecolor + unset NO_COLOR;
  add gemini to isAltScreenStripMode (Ink TUI, repaints inline like Codex/Claude).
- Revert 4 system-routes.test.ts envelope assertions weakened to
  (body.message ?? body.error) back to (body.success === false).
- Add a runGemini() vm-sandbox test that drives the envelope path end-to-end.

Ralph todo-config (PR #135): maxTodos/todoExpirationMinutes are now persisted
and read back — surfaced via the loopState getter (RalphTrackerState) into
toState()/SSE broadcast and restored in restoreState(), mirroring maxIterations.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/web/public/session-ui.js

@@ -653,7 +653,7 @@ Object.assign(CodemanApp.prototype, {
 
     try {
       const statusRes = await fetch('/api/gemini/status');
-      const status = await statusRes.json();
+      const status = (await statusRes.json()).data;
       if (!status.available) {
         this.terminal.writeln('\x1b[1;31m Gemini CLI not found.\x1b[0m');
         this.terminal.writeln('\x1b[90m Install with: npm install -g @google/gemini-cli\x1b[0m');
@@ -674,8 +674,8 @@ Object.assign(CodemanApp.prototype, {
       const data = await res.json();
       if (!data.success) throw new Error(data.error || 'Failed to start Gemini');
 
-      if (data.sessionId) {
-        await this.selectSession(data.sessionId);
+      if (data.data.sessionId) {
+        await this.selectSession(data.data.sessionId);
       }
 
       this.terminal.focus();
@@ -796,6 +796,8 @@ Object.assign(CodemanApp.prototype, {
         enabled: ralphState?.loop?.enabled ?? session.ralphLoop?.enabled ?? false,
         completionPhrase: ralphState?.loop?.completionPhrase || session.ralphLoop?.completionPhrase || '',
         maxIterations: ralphState?.loop?.maxIterations || session.ralphLoop?.maxIterations || 0,
+        maxTodos: ralphState?.loop?.maxTodos || session.ralphLoop?.maxTodos,
+        todoExpirationMinutes: ralphState?.loop?.todoExpirationMinutes || session.ralphLoop?.todoExpirationMinutes,
       });
     }