Adds Home Assistant entities for the foreground-process feature shipped
in the media server, plus migrates existing display entities to use HA
translation keys (strings.json / translations/*) so per-language UI text
flows through the standard locale mechanism.
Foreground entities (all share one HA "Foreground" device linked to the
hub via via_device):
- sensor.foreground_process — process name as state + full payload
(pid, exec path, window title, fullscreen flag, monitor, geometry,
is_browser, browser_page_title, browser_url, error) as attributes
- sensor.window_title, sensor.pid, sensor.foreground_monitor,
sensor.process_started (TIMESTAMP device class)
- binary_sensor.fullscreen, binary_sensor.minimized
Data flow:
- ForegroundCoordinator polls GET /api/foreground every 5s (HTTP fallback)
- media_player's WebSocket receiver forwards `foreground` /
`foreground_update` push frames into the coordinator via
apply_websocket_snapshot, so sensors update in near-real-time when WS
is connected and fall back to polling otherwise
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
