- POST /api/v3/config/schedule and /config/dim-schedule accept a disabled per-day schedule with every day off, and keep an off day's times.
- POST /api/v3/config/main answers restart_required only when the save changed a setting the running display does not apply live.
- GET /api/v3/health reports degraded with checks.display_loop.status stopped when the display service is stopped.
- GET /api/v3/display/current-status answers unknown (null fields) after the display stops instead of the cached last state. New web_interface.display_state.display_gone().
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Adds state.get / state.subscribe to the display's control socket (StateHub in src/ipc/server.py). The web interface holds one subscription per process (web_interface/display_state.py) and reads current-status, on-demand status, plugin runtime and /health's display_loop from it, falling back to the cache keys and heartbeat file. While the socket serves readers, display_current_state and plugin_runtime_snapshot are written less often (about 1.5 instead of 5 cache writes a minute for 15 s screens).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
