feat(auth): replace cookie/api-key auth with JWT Bearer tokens, separate UI from API

- Add JWT Bearer token validation to Rust API via OIDC provider JWKS
  with automatic key rotation and 1-hour cache
- Remove x-api-key auth support and built-in web UI from furumi-web-player,
  leaving it as a pure API server
- Add /auth/token endpoint to Node player server to expose OIDC access
  tokens to the frontend
- Move Node player auth endpoints from /api/* to /auth/* to avoid
  path conflicts with Rust API
- Add static file serving to Node Express server for production
  single-container deployment
- Fix SameSite=Strict cookie issue breaking OIDC redirect flow (use Lax)
- Add Dockerfile.node-player with multi-stage Node.js build
- Add CI workflows for node-player Docker image (dev + release)
- Optimize Rust Dockerfiles with dependency caching layer
- Update docker-compose with OIDC env vars and OLLAMA_MODEL support
- Cherry-pick agent LLM client fixes from DEV branch

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -1,4 +1,4 @@
 /target
-/inbox
-/storage
+/docker/inbox
+/docker/storage
 .env