Navi Code: Phase 2 — CLI terminal client, tests, docs ...

- Add clients/terminal package: config, state, REST API wrappers, WebSocket
  client, renderer, and click-based interactive CLI.
- Wire navi-code console script via pyproject.toml.
- Add unit and WebSocket integration tests for the terminal client.
- Update docs/profiles.md, docs/config.md, README.md with navi_code profile
  and default-profile instructions.
- Add docs/navi_code.md setup guide and docs/navi_code_cli.md usage reference.
- Fix lint in new test files and test_auth_disabled.py.

Tested: 459 passed, 1 skipped (excluded unrelated websocket test).

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

Navi Code: Phase 1 — terminal-first profile, default profile mechanism, env/persona, tests ...

- Add navi_code profile (terminal-first coding assistant)
- Add NAVI_DEFAULT_PROFILE_ID setting and POST /sessions default profile fallback
- Add persona_navi_code.txt and .env.navi_code.example
- Add docs/plan_navi_code.md phased plan
- Update tests to verify default-profile selection in no-auth mode

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

Fix review issues for NAVI_AUTH_ENABLED feature ...

- Return 503 from /auth/login and /auth/callback when NAVI_AUTH_ENABLED=false
- Return model_copy() of _ANONYMOUS_USER to prevent accidental mutation
- Clean up __import__(datetime) in auth DDL
- Reorder FakeChatSession definition before use in tests
- Remove dead monkeypatch code in no-auth integration fixture
- Add unit test for get_current_user_ws in no-auth mode
- Add integration tests rejecting OAuth endpoints in no-auth mode

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

Add NAVI_AUTH_ENABLED switch for optional auth ...

- Add navi_auth_enabled setting (default true) to navi/config.py and .env.example
- When disabled, treat every request as anonymous admin user (id='anonymous')
- Create/update fixed anonymous navi_users row on startup
- Bypass OAuth/cookie/API-token resolution in navi/auth/deps.py
- Update /auth/status to return {enabled, configured}
- Log security warning on startup when auth is disabled
- Update webclient: skip fetchMe/login screen, show Local mode footer,
  expose /admin link, warn in API keys panel
- Rebuild webclient production bundle
- Add unit and integration tests for no-auth mode
- Update docs: auth.md, config.md, api.md, api_tokens.md, sessions.md,
  websocket.md, mechanics.md, index.md

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