feat: propagate title_callback in TUI gateway for real-time title updates

[MP329COde]

Summary

When a conversation title is auto-generated after the first assistant response, the TUI gateway now emits a session.info event to notify connected clients (WebUI, Desktop app) of the new title in real time.

Problem

Previously, the TUI gateway called maybe_auto_title() without a title_callback or main_runtime, so:

• Connected clients never saw the title update until a page refresh
• The title generator could not use the session's model/provider for generation, falling back to defaults

Solution

• Added a _title_generated callback that emits session.info via _emit() when a title is generated
• Passed main_runtime with the agent's model/provider/base_url/api_key/api_mode so the title generator can use the same provider as the session
• Aligns the TUI gateway with the main gateway behavior (which already propagates title callbacks for Telegram topic renames)

Testing

• Verified the patch applies cleanly and passes existing linting
• The change is minimal and defensive (wrapped in try/except like the existing gateway pattern)

[tonydwb]

Code Review Summary

Verdict: Approved

Overview

Propagates the title_callback through the TUI gateway to enable real-time title updates when maybe_auto_title generates a title. Also passes main_runtime dict (model, provider, base_url, api_key, api_mode) to maybe_auto_title for context-aware title generation.

Assessment

• Correctness: Correct closure-based callback (_title_generated) with session-key captured via default argument to avoid late-binding issues. agent attributes accessed defensively with getattr(..., None).
• Code Quality: Clean, focused. The callback is properly scoped to emit session.info to connected clients when a title is auto-generated.
• Security: No security concerns — only exposes metadata to the session info stream.

Looks Good

• Proper closure: _sid=_effective_sid default arg captures current session key
• Defensive getattr for optional agent attributes
• Graceful exception handling in the callback (swallows exceptions silently)

---

Reviewed by Hermes Agent

[teknium1]

Thanks for identifying the missing runtime handoff. The diagnosis remains partly valid on current main: tui_gateway/server.py:9260-9272 still calls maybe_auto_title() without main_runtime.

Problems

• The live-update part has since been implemented differently. Commit 4e023f5bc990ac430d38a220c74162bbe92293f9 added the current session.title callback at tui_gateway/server.py:9266-9271; Desktop consumes it at apps/desktop/src/app/session/hooks/use-message-stream/gateway-event.ts:358-367. The PR's older session.info callback should not be restored.
• No regression test covers runtime forwarding; the present TUI test at tests/test_tui_gateway_server.py:6193-6228 checks only positional arguments.

Suggested changes

• Re-scope the salvage to pass _main_runtime_from_agent(agent) (tui_gateway/server.py:6272-6288) into the current title call, preserving the existing session.title event.
• Add focused assertions for the runtime payload and callback event.

Automated hermes-sweeper review.

[teknium1]

Thanks for the contribution. Closing as superseded — both halves are now on main:

• title_callback in the TUI gateway: main's call site already passes title_callback and emits a targeted session.title event (a narrower push than this PR's session.info refresh), so the live-rename behavior you wanted ships today.
• main_runtime: landed via PR fix(titles): use active runtime for TUI and ACP sessions (salvage #62983) #66062 (salvaging fix(titles): use active runtime for gateway sessions #62983, which was current against main and carried tests for both the TUI and ACP suites — this branch had conflicted after the call site moved).

The gap you identified was real on both counts; the fixes just arrived through fresher branches.