Summary

• stop the embedded TUI from creating a persisted session as soon as the dashboard Chat route mounts
• lazily create the TUI session on first prompt submit, with an in-flight guard to avoid duplicate first-session creation
• stop the dashboard Chat sidebar from creating its own sidecar session on mount; it now adopts the PTY session from session.info events

Why

Opening the dashboard Chat page currently creates empty source=tui rows even when the user is only browsing. In the dashboard this makes the session list noisy and makes resuming real conversations harder. Session persistence should happen when a conversation begins, not when the route renders.

How to test

1. Start the dashboard with embedded chat enabled: hermes dashboard --host 127.0.0.1 --port 9119 --tui --no-open
2. Open /chat without sending a prompt.
3. Confirm no new source=tui session row is persisted.
4. Send a prompt and confirm a TUI session is created normally.

Platforms tested

• macOS 15.5 / Darwin, local dashboard runtime smoke in Chromium
• Cross-platform impact considered: this change is limited to TypeScript/React TUI and dashboard session lifecycle code; it does not add OS-specific file, process, shell, or path handling.

Verification

• npm run type-check --prefix ui-tui
• npm test --prefix ui-tui -- createGatewayEventHandler
• npm run build --prefix web
• Runtime smoke: launched a clean temporary HERMES_HOME dashboard with --tui, loaded /chat in Chromium, and confirmed state.db still had 0 sessions / 0 empty TUI sessions after page load.

Full test suite note

• Attempted the contributing-guide command via the repo venv: ./venv/bin/pytest tests/ -v
• Result in this local checkout: 104 failed, 17249 passed, 52 skipped, 210 warnings, 1 error in 174.86s
• The failures are outside this patch's touched TUI/dashboard files, including existing gateway/Discord/config/tool tests and an import error collecting tests/gateway/test_session.py (normalize_whatsapp_identifier missing from gateway.session).