feat(cli): set terminal tab title to "<persona>: <session title>"

[tsemana]

Summary

Emit OSC 0 (window/tab title) and OSC 7 (working directory) from interactive hermes chat sessions so terminals like Warp, iTerm2, Kitty, WezTerm, Ghostty, and tmux display a useful, agent-aware label per tab — matching the format other agentic CLIs (Claude Code, Codex) use in their tabs.

Format: <Persona>: <session title>

Example: Helm: Plan Hermes agent console with Superset UI features

The persona name is resolved from (in order):

1. Optional agent.persona_name config key
2. The Name: line in ~/.hermes/SOUL.md
3. The first # heading in SOUL.md
4. Fallback to "Hermes"

The session title comes from the existing SessionDB.get_session_title(session_id).

What changed

• New module: hermes_cli/terminal_title.py — OSC emission with sanitisation, truncation, persona resolution, and atexit-restore.
• Wired into cli.py at three spots (each guarded by try/except, so a failure here never breaks chat):
  • After self.session_id = … in the chat session ctor — initial emit
  • After the deferred set_session_title(...) apply — refresh once title generated
  • After the in-chat /title rename success — refresh
• ACP no-op: acp_adapter/__main__.py sets HERMES_DISABLE_TAB_TITLE=1 because the controlling editor draws its own chrome and stdout is reserved for JSON-RPC.
• Tests: 16 unit tests in tests/cli/test_terminal_title.py.

Safety

The module is a silent no-op when:

• stdout/stderr aren't TTYs (pipes, captured output, CI)
• TERM is unset or dumb
• HERMES_DISABLE_TAB_TITLE=1 (set automatically in ACP mode)

It also:

• Sanitises control characters / ESC / BEL out of titles to prevent injection
• Truncates titles to 120 chars (with ellipsis)
• Restores cleared title on normal interpreter exit
• Emits to /dev/tty (preferred) or sys.stderr so output never lands in captured stdout

Every call site in cli.py is wrapped in try: … except Exception: pass — emission is best-effort.

Test plan

• pytest tests/cli/test_terminal_title.py — 16/16 passing
• python -c "import ast; ast.parse(open('cli.py').read())" — syntax valid
• Module imports cleanly (from hermes_cli import terminal_title)
• Manual smoke in Warp / iTerm2: tab updates after first turn (reviewers welcome to verify)
• Manual smoke under hermes acp: no escape sequences leak into JSON-RPC stream

Why

Agentic CLIs are increasingly run in many parallel terminal tabs. Without a tab title, vertical-tab UIs (Warp, WezTerm) just show the binary name + cwd — indistinguishable across sessions. Other agent CLIs (Claude Code, Codex) emit OSC titles with their conversation summary, so users can scan their tab strip and find the right session. This brings Hermes to parity for the universal title/cwd portion. (Per-agent icons in Warp are detected internally by Warp and not settable via OSC; that's a separate upstream Warp request.)

[teknium1]

Thanks for the terminal-title work. Current main already has a related TUI implementation: ui-tui/src/app/useMainApp.ts:584 emits an OSC 0 title containing the live session title, model, and cwd; this was added by d33965396.

Problems

• hermes_cli/terminal_title.py:204 does not implement the advertised agent.persona_name behavior. update_for_session() calls resolve_persona_name() without config_value; the helper only honors that setting when it is supplied by its caller.
• The PR also adds the unrelated LifeOS context engine (plugins/context_engine/lifeos/__init__.py, 949 lines) and changes run_agent.py to inject prefetched context each turn. Please keep a terminal-title PR scoped to terminal-title behavior.
• hermes_cli/terminal_title.py:52 opens /dev/tty before any stdio-TTY check, so redirected stdout/stderr can still produce OSC output through a controlling terminal, contrary to the stated no-op contract.

Suggested changes

• Split the LifeOS/context-engine commits into a separate contribution.
• Wire agent.persona_name through the config loader and add an end-to-end emission test.
• Define and test the redirected-stdio behavior before retaining the /dev/tty path.

Automated hermes-sweeper review.

[teknium1]

update_for_session() never loads or passes agent.persona_name, so this always skips the first advertised resolution source. Please retrieve the configured value here (or at a single shared call site) and add an integration test that proves it reaches the OSC payload.

[teknium1]

This opens the controlling terminal even when stdout and stderr are pipes, so the implementation does not satisfy the stated no-op behavior for captured/piped output. Gate this on the intended interactive condition, or explicitly document and test the controlling-TTY behavior.

[OutThisLife]

Superseded by #74654 (classic CLI) and #74683 (TUI). #74654 covers the same terminal tab title feature at 204 lines vs 1917 here, with the OSC 1/2 lifecycle, config gate, and session title on current main. Closing to consolidate; the core implementation lives on.