feat: response-viewer support for Codex sessions

The response-viewer (eye) currently reads only ~/.claude/projects — for
Codex panes it falls back to a raw terminal-buffer dump. This adds a
Codex-aware reader with exact per-pane rollout attribution.

Locating THIS pane's rollout (~/.codex/sessions/**), in confidence order:

1. history match — Session tracks the pane's last Enter
   (codexLastSubmitAt); correlating it against ~/.codex/history.jsonl
   {session_id, ts} entries identifies the thread the pane is ACTUALLY
   on, surviving /resume, /new and /fork typed inside the codex TUI.
   An entry is credited to the pane whose Enter is closest, so menu
   keystrokes in other panes can't steal attribution.
2. originator match — codex panes are spawned with
   CODEX_INTERNAL_ORIGINATOR_OVERRIDE=codeman_<sessionId>, which codex
   (verified on 0.144.1) writes into session_meta.originator of every
   rollout it creates.
3. resume-id match — resumed rollouts keep their original session_meta
   (codex appends without rewriting), but the uuid is in the filename.
4. cwd+mtime heuristic — case-blind compare (codex records launch-time
   path case) and rollouts claimed by other panes are excluded.

Reader details: user turns come from event_msg/user_message (real input
only — AGENTS.md / environment_context injections never appear there),
deduped against legacy response_item rows per-text so mixed-version
rollouts keep full history; image inputs render an [image xN]
placeholder; session_meta identity is cached per path (write-once).

Frontend: thread role label follows session mode (Codex/Gemini/
OpenCode); the terminal-buffer fallback is Claude-only — TUI modes show
a clear placeholder instead of a repaint dump.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/session.ts

@@ -2252,11 +2252,29 @@ export class Session extends EventEmitter {
    * ```
    */
   write(data: string): void {
+    this._trackCodexSubmit(data);
     if (this.ptyProcess) {
       this.ptyProcess.write(data);
     }
   }
 
+  // ── Codex thread tracking ─────────────────────────────────────────────
+  // When a codex pane last submitted a message (Enter). The response-viewer
+  // correlates this against ~/.codex/history.jsonl entry timestamps to find
+  // the thread the pane is ACTUALLY on — the only signal that survives
+  // /resume, /new and /fork typed inside the codex TUI itself.
+  private _codexLastSubmitAt = 0;
+
+  get codexLastSubmitAt(): number {
+    return this._codexLastSubmitAt;
+  }
+
+  private _trackCodexSubmit(data: string): void {
+    if (this.mode === 'codex' && (data.includes('\r') || data.includes('\n'))) {
+      this._codexLastSubmitAt = Date.now();
+    }
+  }
+
   /**
    * Per-client highest-applied input sequence, for exactly-once input delivery.
    * Keyed by the web client's stable `clientId`. Bounded so many devices over a
@@ -2310,6 +2328,7 @@ export class Session extends EventEmitter {
    * ```
    */
   async writeViaMux(data: string): Promise<boolean> {
+    this._trackCodexSubmit(data);
     if (this._mux && this._muxSession) {
       return this._mux.sendInput(this.id, data);
     }