State stream ticks carry the volatile timestamps (display.last_updated, plugins.published_at), so current-status and the plugin runtime stay fresh while one mode stays on screen.
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>
