Fix settings route switching and document API token system ...

- App.vue: make route reactive via ref + getRouteFromHash() so
  #settings toggles work without page reload
- docs/api_tokens.md: new comprehensive API token auth doc
- docs/api.md: add /api-tokens REST endpoints
- docs/auth.md: add token flow architecture diagram and resolution order
- docs/websocket.md: add auth section with cookie vs query-param token
- docs/architecture.md: update to AgentSessionOrchestrator + ToolContext
- docs/tools.md: add gnexus-creds MCP tools
- docs/index.md: link to api_tokens.md
- Rebuild webclient dist

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Docs audit: fix outdated references (PostgreSQL, Vue client, profiles, tools) ...

- architecture.md: SQLite → PostgreSQL + pgvector
- README.md: vanilla JS → Vue 3 + Pinia, remove smart_home, update temps
- profiles.md: remove smart_home, add discuss, update temperatures
- tools.md: add missing built-in tools, update user tools list
- sessions.md: fix outdated references
- NAVI.md: sync with current stack
- persona.txt: update self-extension and content_publish guidance
- content_publish.md manual: reflect session_dir-based no-copy design
- content_store.py & content_publish.py: inline with docs

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

WelcomeScreen polish, root-path fix, docs update ...

- Move mobile sidebar button to top-left corner (no header bar backdrop)
- Show WelcomeScreen on / with no hash instead of auto-loading first session
- Docs: document Ollama multi-server fallback, model priority lists, OLLAMA_BACKENDS_FILE

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Add backend documentation ...

10 markdown files covering all backend subsystems: architecture,
agent loop, tool system, sessions, WebSocket protocol, profiles,
memory, config, and API reference. Structured for AI readability
with a single entry point (docs/index.md) and cross-references.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>