Adds cross-platform foreground-window tracking and exposes it over REST
(/api/foreground) and the existing WebSocket feed.
- foreground_service.py: Windows probe via ctypes (HANDLE-correct argtypes
to avoid 64-bit handle truncation); macOS via AppKit; Linux via Xlib
(Wayland returns unavailable). TTL cache + per-platform fallback.
- browser_url_service.py: when foreground is a recognised browser, extract
the page title from the window title (browser-name suffix stripped) and
surface `is_browser` + `browser_page_title`. Optional UIA-based URL
extraction behind MEDIA_SERVER_BROWSER_UIA env flag (off by default —
Chromium browsers keep their accessibility tree dormant otherwise).
- websocket_manager: poll foreground every 1s inside the existing status
loop, broadcast `foreground` on connect and `foreground_update` on
change. Diff only on user-visible fields to avoid geometry spam.
- WebUI: new editorial card rendered under the monitor list on the
Display tab — process name, window title, fullscreen/minimized/monitor
chips, browser block when applicable, exe path, PID, started-ago,
geometry, platform. 16px inter-section gap matches Settings cadence.
- i18n: 25 new keys added to both en.json and ru.json.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
