feat(foreground): track topmost process + browser page title

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>

config.example.yaml

@@ -1,7 +1,13 @@
 # Media Server Configuration
 # Copy this file to config.yaml and customize as needed.
-# By default, authentication is DISABLED (no tokens = open access).
-# To enable auth, uncomment and configure the api_tokens section below.
+#
+# Secure-by-default: the server binds to loopback (127.0.0.1) only and refuses
+# to bind a non-loopback address with no tokens configured.
+#
+# To expose on the LAN you must do ONE of:
+#   1. Configure api_tokens below AND change host to "0.0.0.0", OR
+#   2. Set `allow_lan_without_auth: true` (LAN-open, no auth — insecure on
+#      hostile networks, only acceptable on a trusted home LAN).
 
 # API Tokens - Multiple tokens with friendly labels
 # This allows you to identify which client is making requests in the logs
@@ -11,8 +17,9 @@
 #   web_ui: "your-web-ui-token-here"
 
 # Server settings
-host: "0.0.0.0"
+host: "127.0.0.1"
 port: 8765
+# allow_lan_without_auth: true   # uncomment + change host to 0.0.0.0 for LAN-open mode
 
 # Custom scripts
 scripts:

media_server/main.py

@@ -22,6 +22,7 @@ from .routes import (
     browser_router,
     callbacks_router,
     display_router,
+    foreground_router,
     health_router,
     links_router,
     media_router,
@@ -241,6 +242,7 @@ def create_app() -> FastAPI:
     app.include_router(browser_router)
     app.include_router(callbacks_router)
     app.include_router(display_router)
+    app.include_router(foreground_router)
     app.include_router(health_router)
     app.include_router(links_router)
     app.include_router(media_router)
@@ -320,44 +322,53 @@ def main():
             print("\nAuthentication is DISABLED (no tokens configured)")
         return
 
+    # Stderr is invisible when launched via wscript / pythonw (Start Menu shortcut,
+    # autostart). Mirror pre-uvicorn failures to a file in the config dir so the
+    # next silent boot failure is diagnosable.
+    def _fatal(msg: str, exit_code: int = 1) -> None:
+        print(msg, file=sys.stderr)
+        try:
+            log_path = get_config_dir() / "startup-errors.log"
+            from datetime import datetime
+            with open(log_path, "a", encoding="utf-8") as f:
+                f.write(f"[{datetime.now().isoformat(timespec='seconds')}] {msg}\n")
+        except OSError:
+            pass
+        sys.exit(exit_code)
+
     # First-run bootstrap: if no config has ever been written, generate one
     # with a random token instead of starting in the insecure "no-auth" mode.
     config_path = get_config_dir() / "config.yaml"
     if not config_path.exists() and not settings.api_tokens:
         try:
             generate_default_config(config_path)
-            print(
+            _fatal(
                 f"\nFirst run: generated default config at {config_path}.\n"
                 "Run --show-token to retrieve the API token, then restart.",
-                file=sys.stderr,
+                exit_code=0,
             )
-            sys.exit(0)
         except OSError as e:
             print(f"WARNING: could not bootstrap config: {e}", file=sys.stderr)
 
     # Refuse to bind a non-loopback address with no tokens, unless explicitly opted in.
     non_loopback = args.host not in ("127.0.0.1", "localhost", "::1")
     if non_loopback and not settings.api_tokens and not settings.allow_lan_without_auth:
-        print(
+        _fatal(
             "ERROR: refusing to bind a non-loopback address with no api_tokens configured.\n"
             "Either set api_tokens in config.yaml, bind to 127.0.0.1,"
-            " or set allow_lan_without_auth: true in config.yaml to override.",
-            file=sys.stderr,
+            " or set allow_lan_without_auth: true in config.yaml to override."
         )
-        sys.exit(1)
 
     # Check if port is available before starting
     with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
         try:
             sock.bind((args.host if args.host != "0.0.0.0" else "127.0.0.1", args.port))
         except OSError:
-            print(
+            _fatal(
                 f"ERROR: Port {args.port} is already in use. "
                 f"Another instance of Media Server may be running.\n"
-                f"Stop the other process or use --port to pick a different port.",
-                file=sys.stderr,
+                f"Stop the other process or use --port to pick a different port."
             )
-            sys.exit(1)
 
     from .tray import PYSTRAY_AVAILABLE, TrayManager
 

media_server/routes/__init__.py

@@ -4,6 +4,7 @@ from .audio import router as audio_router
 from .browser import router as browser_router
 from .callbacks import router as callbacks_router
 from .display import router as display_router
+from .foreground import router as foreground_router
 from .health import router as health_router
 from .links import router as links_router
 from .media import router as media_router
@@ -14,6 +15,7 @@ __all__ = [
     "browser_router",
     "callbacks_router",
     "display_router",
+    "foreground_router",
     "health_router",
     "links_router",
     "media_router",

media_server/routes/foreground.py

@@ -0,0 +1,26 @@
+"""Foreground (topmost) window/process API."""
+
+import asyncio
+import logging
+
+from fastapi import APIRouter, Depends
+
+from ..auth import verify_token
+from ..services.foreground_service import get_foreground_info
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api/foreground", tags=["foreground"])
+
+
+@router.get("")
+async def get_foreground(
+    refresh: bool = False, _: str = Depends(verify_token)
+) -> dict:
+    """Return metadata about the foreground window and owning process.
+
+    The probe is cached for ~500ms server-side; pass ``?refresh=1`` to bypass
+    the cache for one-shot queries.
+    """
+    info = await asyncio.to_thread(get_foreground_info, refresh)
+    return info.to_dict()

media_server/services/browser_url_service.py

@@ -0,0 +1,296 @@
+"""Extract page-level metadata from a focused desktop web browser.
+
+The browser's window title is the reliable signal — every major browser
+formats it as ``"<page title> - <Browser Name>"``, so stripping the suffix
+gives us the page title for free.
+
+URL extraction was attempted via UI Automation (UIA), but Chromium-based
+browsers (Chrome/Edge/Brave/Vivaldi) keep their accessibility tree dormant
+unless a screen reader is active or ``--force-renderer-accessibility`` is
+set — neither is something we want to require from end users. The UIA
+machinery is still here behind a feature flag in case a future caller
+opts into the accessibility-flag path; by default we just return the
+page title and leave ``url=None``.
+
+Other platforms (macOS via AppleScript, Linux via AT-SPI) are out of scope
+for this iteration.
+"""
+
+from __future__ import annotations
+
+import logging
+import os
+import platform
+import threading
+from dataclasses import dataclass
+
+logger = logging.getLogger(__name__)
+
+# UIA URL extraction is opt-in because Chromium browsers keep their
+# accessibility tree dormant unless the user starts the browser with
+# ``--force-renderer-accessibility`` (or a screen reader is running).
+# Without that, `FindAll` throws and we'd burn 5s per probe retrying.
+# Set MEDIA_SERVER_BROWSER_UIA=1 to enable; default off.
+_UIA_ENABLED = os.environ.get("MEDIA_SERVER_BROWSER_UIA", "").lower() in (
+    "1", "true", "yes", "on"
+)
+
+
+# Known browser executables (lowercase, .exe-stripped). Used to decide
+# whether to spend the UIA query budget on this foreground process.
+BROWSER_PROCESS_HINTS: frozenset[str] = frozenset({
+    "chrome",
+    "msedge",
+    "firefox",
+    "brave",
+    "opera",
+    "vivaldi",
+    "yandex",
+    "browser",  # Yandex Browser sometimes reports as browser.exe
+    "arc",
+    "thorium",
+})
+
+
+@dataclass(frozen=True)
+class BrowserPageInfo:
+    url: str | None = None
+    page_title: str | None = None
+
+
+_EMPTY = BrowserPageInfo()
+
+
+def is_browser_process(process_name: str | None) -> bool:
+    """Return True when ``process_name`` looks like a supported browser."""
+    if not process_name:
+        return False
+    base = process_name.lower()
+    if base.endswith(".exe"):
+        base = base[:-4]
+    return base in BROWSER_PROCESS_HINTS
+
+
+def _strip_browser_suffix(title: str | None, process_name: str | None) -> str | None:
+    """Pull the page title out of the browser's window title.
+
+    Most browsers format their window title as ``"<page> - <Browser Name>"``.
+    We strip the trailing suffix so consumers get the page title alone. If
+    the suffix can't be matched, return the raw title unchanged.
+    """
+    if not title:
+        return None
+    suffixes = (
+        " - Google Chrome",
+        " — Google Chrome",
+        " - Microsoft Edge",
+        " - Microsoft Edge",
+        " — Mozilla Firefox",
+        " - Mozilla Firefox",
+        " - Brave",
+        " - Opera",
+        " - Vivaldi",
+        " - Yandex",
+    )
+    for s in suffixes:
+        if title.endswith(s):
+            return title[: -len(s)].strip() or None
+    return title
+
+
+# ─── UIA lookup (Windows) ───────────────────────────────────────────
+
+# UIA control type / property constants we need. Avoiding the full
+# UIAutomationClient typelib generation — those constants are stable.
+_UIA_EditControlTypeId = 50004
+_UIA_ControlTypePropertyId = 30003
+_UIA_ValueValuePropertyId = 30045
+_UIA_NamePropertyId = 30005
+_UIA_ValuePatternId = 10002
+_TreeScope_Descendants = 4
+_PropertyConditionFlags_IgnoreCase = 1
+
+
+# Lazy import + per-thread COM init.
+_uia_lock = threading.Lock()
+_uia_singleton = None
+_uia_load_error: str | None = None
+_uia_thread_local = threading.local()
+
+
+def _ensure_com() -> None:
+    """Initialise COM on the current thread (idempotent per thread)."""
+    if getattr(_uia_thread_local, "initialised", False):
+        return
+    try:
+        import comtypes  # type: ignore
+
+        # COINIT_APARTMENTTHREADED is required by UIA; comtypes' default
+        # CoInitializeEx already passes that flag.
+        comtypes.CoInitialize()
+        _uia_thread_local.initialised = True
+    except Exception as e:
+        logger.debug("CoInitialize failed: %s", e)
+
+
+def _get_uia():
+    """Return the IUIAutomation singleton, or None if unavailable."""
+    global _uia_singleton, _uia_load_error
+    if _uia_singleton is not None:
+        return _uia_singleton
+    if _uia_load_error is not None:
+        return None
+    with _uia_lock:
+        if _uia_singleton is not None:
+            return _uia_singleton
+        try:
+            import comtypes.client  # type: ignore
+
+            # CLSID for CUIAutomation. Using GetActiveObject would fail,
+            # so we cocreate. comtypes.client.CreateObject keeps the COM
+            # plumbing tidy.
+            _uia_singleton = comtypes.client.CreateObject(
+                "{ff48dba4-60ef-4201-aa87-54103eef594e}",
+                interface=comtypes.client.GetModule(
+                    "UIAutomationCore.dll"
+                ).IUIAutomation,
+            )
+            return _uia_singleton
+        except Exception as e:
+            _uia_load_error = str(e)
+            logger.info("UIA unavailable; browser URL extraction disabled: %s", e)
+            return None
+
+
+def _find_address_bar_value(hwnd: int) -> str | None:
+    """Walk the UIA tree under ``hwnd`` looking for the URL Edit control.
+
+    Strategy: find every descendant Edit control, then pick the first one
+    whose Name contains an address-bar hint, or — failing that — the first
+    one whose value parses as a URL-ish string. Browsers expose extra Edit
+    controls (search bars, find-in-page) so name matching is the reliable
+    signal; the URL-ish fallback covers locale variants we haven't seen.
+    """
+    _ensure_com()
+    uia = _get_uia()
+    if uia is None:
+        return None
+
+    try:
+        element = uia.ElementFromHandle(hwnd)
+        if not element:
+            return None
+
+        # Build a condition matching ControlType=Edit, then enumerate.
+        edit_condition = uia.CreatePropertyCondition(
+            _UIA_ControlTypePropertyId, _UIA_EditControlTypeId
+        )
+        edits = element.FindAll(_TreeScope_Descendants, edit_condition)
+        count = edits.Length if edits else 0
+        if count == 0:
+            return None
+
+        # Hints (lowercase) used to identify the address bar by its Name
+        # property. Covers en-US plus a few common locales / browsers.
+        name_hints = (
+            "address",          # Chrome/Edge: "Address and search bar"
+            "адрес",            # Chrome ru: "Адресная строка и строка поиска"
+            "адресная",
+            "search with",      # Firefox: "Search with Google or enter address"
+            "поиск или ввод",   # Firefox ru
+            "url",
+            "location",
+        )
+
+        # First pass: name-based match (high confidence).
+        candidates: list[tuple[int, str]] = []
+        for i in range(count):
+            edit = edits.GetElement(i)
+            try:
+                name = (edit.CurrentName or "").lower()
+            except Exception:
+                name = ""
+            try:
+                value = edit.GetCurrentPropertyValue(_UIA_ValueValuePropertyId)
+            except Exception:
+                value = None
+            if value is None:
+                continue
+            value_str = str(value)
+            for h in name_hints:
+                if h in name:
+                    return value_str
+            candidates.append((i, value_str))
+
+        # Second pass: URL-ish fallback. Pick the first candidate that
+        # looks like a URL; this catches browser/locale combos we haven't
+        # listed above.
+        for _i, v in candidates:
+            lv = v.lower()
+            if (
+                lv.startswith("http://")
+                or lv.startswith("https://")
+                or lv.startswith("about:")
+                or lv.startswith("chrome://")
+                or lv.startswith("edge://")
+                or lv.startswith("brave://")
+                or lv.startswith("file://")
+                or lv.startswith("ftp://")
+            ):
+                return v
+
+        return None
+    except Exception as e:
+        logger.debug("UIA address-bar lookup failed: %s", e)
+        return None
+
+
+# ─── Per-(hwnd, title) cache ────────────────────────────────────────
+
+_cache_lock = threading.Lock()
+_cache_key: tuple[int | None, str | None] = (None, None)
+_cache_value: BrowserPageInfo = _EMPTY
+
+
+def get_browser_page(
+    *,
+    hwnd: int | None,
+    process_name: str | None,
+    window_title: str | None,
+) -> BrowserPageInfo:
+    """Return the URL + page title for the foreground browser tab, if any.
+
+    Callers pass the already-resolved foreground HWND/title/process_name so
+    this service doesn't re-walk Win32 to find them. Returns ``_EMPTY`` for
+    non-browser processes or when UIA can't resolve the URL.
+    """
+    if not is_browser_process(process_name):
+        return _EMPTY
+    if platform.system() != "Windows":
+        # macOS/Linux paths not implemented in this iteration.
+        return _EMPTY
+    if not hwnd:
+        return _EMPTY
+
+    global _cache_key, _cache_value
+    key = (hwnd, window_title)
+    with _cache_lock:
+        if key == _cache_key and _cache_value is not _EMPTY:
+            return _cache_value
+
+    url = _find_address_bar_value(hwnd) if _UIA_ENABLED else None
+    page_title = _strip_browser_suffix(window_title, process_name)
+    info = BrowserPageInfo(url=url, page_title=page_title)
+
+    with _cache_lock:
+        _cache_key = key
+        _cache_value = info
+    return info
+
+
+def reset_cache() -> None:
+    """Reset the cache. Useful in tests."""
+    global _cache_key, _cache_value
+    with _cache_lock:
+        _cache_key = (None, None)
+        _cache_value = _EMPTY

media_server/services/foreground_service.py

@@ -0,0 +1,514 @@
+"""Foreground (topmost) window/process tracking.
+
+Reports the process that currently owns the foreground window, plus useful
+metadata (window title, executable path, monitor index, whether the window
+covers a full monitor, process start time).
+
+All probes happen behind a short TTL cache so the WebSocket status poll and
+per-entity HA polls don't pay the OS call cost on every tick.
+
+Windows uses the Win32 API via ``ctypes`` (no extra dependency) and falls back
+gracefully when individual probes fail. Linux/macOS implementations are
+best-effort and return ``available=False`` when the required tooling is
+missing, so the rest of the stack keeps working.
+"""
+
+from __future__ import annotations
+
+import logging
+import platform
+import threading
+import time
+from dataclasses import asdict, dataclass, field
+
+logger = logging.getLogger(__name__)
+
+_CACHE_TTL = 0.5  # seconds — fast enough for WebSocket broadcast loop
+
+
+@dataclass(frozen=True)
+class ForegroundInfo:
+    """Snapshot of the foreground window/process."""
+
+    available: bool
+    pid: int | None = None
+    process_name: str | None = None
+    executable_path: str | None = None
+    window_title: str | None = None
+    window_handle: int | None = None
+    is_fullscreen: bool = False
+    is_minimized: bool = False
+    monitor_id: int | None = None
+    monitor_geometry: dict[str, int] | None = None
+    window_geometry: dict[str, int] | None = None
+    started_at: float | None = None
+    platform: str = field(default_factory=lambda: platform.system())
+    error: str | None = None
+    # Populated only when the foreground process is a recognised web
+    # browser. ``browser_page_title`` is derived from the window title
+    # (suffix stripped); ``browser_url`` requires UIA to succeed.
+    is_browser: bool = False
+    browser_url: str | None = None
+    browser_page_title: str | None = None
+
+    def to_dict(self) -> dict:
+        return asdict(self)
+
+
+_UNAVAILABLE = ForegroundInfo(available=False)
+
+
+class _Cache:
+    """Single-slot TTL cache shared across callers."""
+
+    def __init__(self) -> None:
+        self._lock = threading.Lock()
+        self._value: ForegroundInfo | None = None
+        self._fetched_at: float = 0.0
+
+    def get(self, ttl: float, fetch) -> ForegroundInfo:
+        with self._lock:
+            now = time.monotonic()
+            if self._value is not None and (now - self._fetched_at) < ttl:
+                return self._value
+        # Fetch outside the lock — OS calls can take tens of ms.
+        value = fetch()
+        with self._lock:
+            self._value = value
+            self._fetched_at = time.monotonic()
+        return value
+
+    def invalidate(self) -> None:
+        with self._lock:
+            self._value = None
+            self._fetched_at = 0.0
+
+
+_cache = _Cache()
+
+
+def _probe_windows() -> ForegroundInfo:
+    """Probe foreground window state on Windows via Win32 API."""
+    import ctypes
+    import ctypes.wintypes as wt
+
+    user32 = ctypes.WinDLL("user32", use_last_error=True)
+    kernel32 = ctypes.WinDLL("kernel32", use_last_error=True)
+    psapi = ctypes.WinDLL("psapi", use_last_error=True)
+
+    # CRITICAL: declare argtypes/restype on every Win32 call that returns a
+    # HANDLE/HWND/HMONITOR. ctypes defaults to `c_int` (32-bit) which
+    # silently truncates 64-bit pointer values on x64 — that corrupts the
+    # handle so `CloseHandle()` can either fail or close the wrong kernel
+    # object, and pointer-equality comparisons (monitor index lookup) miss.
+    user32.GetForegroundWindow.restype = wt.HWND
+    user32.GetWindowThreadProcessId.argtypes = [wt.HWND, ctypes.POINTER(wt.DWORD)]
+    user32.GetWindowThreadProcessId.restype = wt.DWORD
+    user32.GetWindowTextLengthW.argtypes = [wt.HWND]
+    user32.GetWindowTextLengthW.restype = ctypes.c_int
+    user32.GetWindowTextW.argtypes = [wt.HWND, wt.LPWSTR, ctypes.c_int]
+    user32.GetWindowTextW.restype = ctypes.c_int
+    user32.IsIconic.argtypes = [wt.HWND]
+    user32.IsIconic.restype = wt.BOOL
+    user32.GetWindowRect.argtypes = [wt.HWND, ctypes.POINTER(wt.RECT)]
+    user32.GetWindowRect.restype = wt.BOOL
+    user32.MonitorFromWindow.argtypes = [wt.HWND, wt.DWORD]
+    user32.MonitorFromWindow.restype = wt.HMONITOR
+    user32.GetMonitorInfoW.argtypes = [wt.HMONITOR, ctypes.c_void_p]
+    user32.GetMonitorInfoW.restype = wt.BOOL
+
+    kernel32.OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]
+    kernel32.OpenProcess.restype = wt.HANDLE
+    kernel32.CloseHandle.argtypes = [wt.HANDLE]
+    kernel32.CloseHandle.restype = wt.BOOL
+    kernel32.QueryFullProcessImageNameW.argtypes = [
+        wt.HANDLE, wt.DWORD, wt.LPWSTR, ctypes.POINTER(wt.DWORD)
+    ]
+    kernel32.QueryFullProcessImageNameW.restype = wt.BOOL
+    kernel32.GetProcessTimes.argtypes = [
+        wt.HANDLE,
+        ctypes.POINTER(wt.FILETIME),
+        ctypes.POINTER(wt.FILETIME),
+        ctypes.POINTER(wt.FILETIME),
+        ctypes.POINTER(wt.FILETIME),
+    ]
+    kernel32.GetProcessTimes.restype = wt.BOOL
+
+    psapi.GetModuleFileNameExW.argtypes = [wt.HANDLE, wt.HMODULE, wt.LPWSTR, wt.DWORD]
+    psapi.GetModuleFileNameExW.restype = wt.DWORD
+
+    hwnd = user32.GetForegroundWindow()
+    if not hwnd:
+        return ForegroundInfo(available=True, error="no foreground window")
+
+    # PID + window thread.
+    pid = wt.DWORD(0)
+    user32.GetWindowThreadProcessId(hwnd, ctypes.byref(pid))
+    pid_val = int(pid.value) if pid.value else None
+
+    # Window title — Unicode.
+    length = user32.GetWindowTextLengthW(hwnd)
+    title_buf = ctypes.create_unicode_buffer(length + 1)
+    user32.GetWindowTextW(hwnd, title_buf, length + 1)
+    window_title = title_buf.value or None
+
+    # Minimized flag.
+    is_minimized = bool(user32.IsIconic(hwnd))
+
+    # Window rect (screen coords).
+    rect = wt.RECT()
+    window_geometry: dict[str, int] | None = None
+    if user32.GetWindowRect(hwnd, ctypes.byref(rect)):
+        window_geometry = {
+            "left": int(rect.left),
+            "top": int(rect.top),
+            "right": int(rect.right),
+            "bottom": int(rect.bottom),
+            "width": int(rect.right - rect.left),
+            "height": int(rect.bottom - rect.top),
+        }
+
+    # Monitor under the window + its geometry.
+    monitor_geometry: dict[str, int] | None = None
+    monitor_id: int | None = None
+    is_fullscreen = False
+    try:
+        MONITOR_DEFAULTTONEAREST = 2
+
+        class MONITORINFO(ctypes.Structure):
+            _fields_ = [
+                ("cbSize", wt.DWORD),
+                ("rcMonitor", wt.RECT),
+                ("rcWork", wt.RECT),
+                ("dwFlags", wt.DWORD),
+            ]
+
+        hmon = user32.MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST)
+        if hmon:
+            mi = MONITORINFO()
+            mi.cbSize = ctypes.sizeof(mi)
+            if user32.GetMonitorInfoW(hmon, ctypes.byref(mi)):
+                monitor_geometry = {
+                    "left": int(mi.rcMonitor.left),
+                    "top": int(mi.rcMonitor.top),
+                    "right": int(mi.rcMonitor.right),
+                    "bottom": int(mi.rcMonitor.bottom),
+                    "width": int(mi.rcMonitor.right - mi.rcMonitor.left),
+                    "height": int(mi.rcMonitor.bottom - mi.rcMonitor.top),
+                }
+                # Fullscreen heuristic: window rect equals monitor rect AND
+                # not minimized. Many media players (VLC, browser fullscreen)
+                # set themselves to exactly the monitor bounds.
+                if window_geometry and not is_minimized:
+                    is_fullscreen = (
+                        window_geometry["left"] == monitor_geometry["left"]
+                        and window_geometry["top"] == monitor_geometry["top"]
+                        and window_geometry["right"] == monitor_geometry["right"]
+                        and window_geometry["bottom"] == monitor_geometry["bottom"]
+                    )
+
+            # Resolve monitor index by enumerating displays in order. Coerce
+            # both the foreground hmon and the per-enum hmon to int so the
+            # equality compare uses 64-bit values consistently regardless of
+            # how ctypes represents the handle internally.
+            try:
+                indexed: list[int] = []
+
+                def _cb(hm, _hdc, _rect, _data):
+                    indexed.append(int(hm) if hm else 0)
+                    return True
+
+                MONITORENUMPROC = ctypes.WINFUNCTYPE(
+                    ctypes.c_int,
+                    wt.HMONITOR,
+                    wt.HDC,
+                    ctypes.POINTER(wt.RECT),
+                    wt.LPARAM,
+                )
+                user32.EnumDisplayMonitors.argtypes = [
+                    wt.HDC, ctypes.POINTER(wt.RECT), MONITORENUMPROC, wt.LPARAM
+                ]
+                user32.EnumDisplayMonitors.restype = wt.BOOL
+                user32.EnumDisplayMonitors(None, None, MONITORENUMPROC(_cb), 0)
+                target = int(hmon) if hmon else 0
+                if target and target in indexed:
+                    monitor_id = indexed.index(target)
+            except Exception as e:
+                logger.debug("Monitor index resolution failed: %s", e)
+    except Exception as e:
+        logger.debug("Monitor info probe failed: %s", e)
+
+    # Process executable path + start time.
+    executable_path: str | None = None
+    process_name: str | None = None
+    started_at: float | None = None
+    if pid_val:
+        PROCESS_QUERY_LIMITED_INFORMATION = 0x1000
+        h_proc = kernel32.OpenProcess(
+            PROCESS_QUERY_LIMITED_INFORMATION, False, pid_val
+        )
+        if h_proc:
+            try:
+                # Image filename — full path. QueryFullProcessImageNameW works
+                # across 32/64-bit boundaries, unlike GetModuleFileNameExW.
+                buf = ctypes.create_unicode_buffer(1024)
+                size = wt.DWORD(len(buf))
+                if kernel32.QueryFullProcessImageNameW(
+                    h_proc, 0, buf, ctypes.byref(size)
+                ):
+                    executable_path = buf.value or None
+                else:
+                    # Fallback via psapi. Return value is the length copied
+                    # into the buffer (0 on failure); ignoring it would leave
+                    # `executable_path` as an empty string from the freshly
+                    # allocated buffer instead of None.
+                    written = psapi.GetModuleFileNameExW(h_proc, None, buf, len(buf))
+                    if written:
+                        executable_path = buf.value or None
+                    else:
+                        logger.debug(
+                            "QueryFullProcessImageNameW + psapi fallback both "
+                            "failed for pid=%s (err=%d)",
+                            pid_val,
+                            ctypes.get_last_error(),
+                        )
+
+                if executable_path:
+                    import os
+                    process_name = os.path.basename(executable_path)
+
+                # Process creation time (FILETIME, 100ns ticks since 1601).
+                creation = wt.FILETIME()
+                exit_t = wt.FILETIME()
+                kernel_t = wt.FILETIME()
+                user_t = wt.FILETIME()
+                if kernel32.GetProcessTimes(
+                    h_proc,
+                    ctypes.byref(creation),
+                    ctypes.byref(exit_t),
+                    ctypes.byref(kernel_t),
+                    ctypes.byref(user_t),
+                ):
+                    ticks = (creation.dwHighDateTime << 32) | creation.dwLowDateTime
+                    # Convert to Unix epoch seconds (1601-01-01 → 1970-01-01).
+                    if ticks:
+                        started_at = (ticks - 116444736000000000) / 10_000_000
+            finally:
+                kernel32.CloseHandle(h_proc)
+
+    return ForegroundInfo(
+        available=True,
+        pid=pid_val,
+        process_name=process_name,
+        executable_path=executable_path,
+        window_title=window_title,
+        window_handle=int(hwnd) if hwnd else None,
+        is_fullscreen=is_fullscreen,
+        is_minimized=is_minimized,
+        monitor_id=monitor_id,
+        monitor_geometry=monitor_geometry,
+        window_geometry=window_geometry,
+        started_at=started_at,
+    )
+
+
+def _probe_macos() -> ForegroundInfo:
+    """Best-effort probe on macOS via AppKit (PyObjC).
+
+    Returns ``available=False`` when PyObjC is not installed — we don't take
+    a hard dependency on it because the typical macOS install path uses pip
+    + the standalone wheel.
+    """
+    try:
+        from AppKit import NSWorkspace  # type: ignore
+        from Quartz import (  # type: ignore
+            CGWindowListCopyWindowInfo,
+            kCGNullWindowID,
+            kCGWindowListOptionOnScreenOnly,
+        )
+    except Exception:
+        return ForegroundInfo(available=False, error="AppKit/Quartz not available")
+
+    try:
+        ws = NSWorkspace.sharedWorkspace()
+        app = ws.frontmostApplication()
+        if app is None:
+            return ForegroundInfo(available=True, error="no frontmost app")
+
+        pid = int(app.processIdentifier())
+        process_name = str(app.localizedName() or "")
+        bundle_url = app.bundleURL()
+        executable_path = str(bundle_url.path()) if bundle_url else None
+        started_at = None
+        launch_date = app.launchDate()
+        if launch_date is not None:
+            started_at = float(launch_date.timeIntervalSince1970())
+
+        # Window title — frontmost on-screen window owned by this PID.
+        window_title: str | None = None
+        try:
+            windows = CGWindowListCopyWindowInfo(
+                kCGWindowListOptionOnScreenOnly, kCGNullWindowID
+            )
+            for w in windows or []:
+                if int(w.get("kCGWindowOwnerPID", -1)) == pid:
+                    name = w.get("kCGWindowName")
+                    if name:
+                        window_title = str(name)
+                        break
+        except Exception as e:
+            logger.debug("CGWindowListCopyWindowInfo failed: %s", e)
+
+        return ForegroundInfo(
+            available=True,
+            pid=pid,
+            process_name=process_name,
+            executable_path=executable_path,
+            window_title=window_title,
+            started_at=started_at,
+        )
+    except Exception as e:
+        logger.debug("macOS foreground probe failed: %s", e)
+        return ForegroundInfo(available=False, error=str(e))
+
+
+def _probe_linux() -> ForegroundInfo:
+    """Best-effort probe on Linux via Xlib (X11 only).
+
+    Wayland sessions intentionally hide window/process info from unprivileged
+    clients, so this returns ``available=False`` on Wayland. The caller still
+    gets a structured response and can render "unavailable" in the UI.
+    """
+    import os
+
+    if os.environ.get("WAYLAND_DISPLAY"):
+        return ForegroundInfo(
+            available=False, error="Wayland session — foreground probe unavailable"
+        )
+
+    try:
+        from Xlib import display, X  # type: ignore  # noqa: F401
+    except Exception:
+        return ForegroundInfo(available=False, error="python-xlib not installed")
+
+    try:
+        d = display.Display()
+        root = d.screen().root
+        NET_ACTIVE_WINDOW = d.intern_atom("_NET_ACTIVE_WINDOW")
+        NET_WM_PID = d.intern_atom("_NET_WM_PID")
+        NET_WM_NAME = d.intern_atom("_NET_WM_NAME")
+        UTF8_STRING = d.intern_atom("UTF8_STRING")
+
+        active = root.get_full_property(NET_ACTIVE_WINDOW, X.AnyPropertyType)
+        if not active or not active.value:
+            return ForegroundInfo(available=True, error="no active window")
+        win_id = int(active.value[0])
+        win = d.create_resource_object("window", win_id)
+
+        pid_prop = win.get_full_property(NET_WM_PID, X.AnyPropertyType)
+        pid_val = int(pid_prop.value[0]) if pid_prop and pid_prop.value else None
+
+        name_prop = win.get_full_property(NET_WM_NAME, UTF8_STRING)
+        window_title = (
+            name_prop.value.decode("utf-8", "replace") if name_prop and name_prop.value else None
+        )
+
+        process_name: str | None = None
+        executable_path: str | None = None
+        started_at: float | None = None
+        if pid_val:
+            try:
+                exe = os.readlink(f"/proc/{pid_val}/exe")
+                executable_path = exe
+                process_name = os.path.basename(exe)
+            except OSError as e:
+                logger.debug("readlink /proc/%d/exe failed: %s", pid_val, e)
+            try:
+                started_at = os.stat(f"/proc/{pid_val}").st_ctime
+            except OSError as e:
+                logger.debug("stat /proc/%d failed: %s", pid_val, e)
+
+        return ForegroundInfo(
+            available=True,
+            pid=pid_val,
+            process_name=process_name,
+            executable_path=executable_path,
+            window_title=window_title,
+            window_handle=win_id,
+            started_at=started_at,
+        )
+    except Exception as e:
+        logger.debug("Linux foreground probe failed: %s", e)
+        return ForegroundInfo(available=False, error=str(e))
+
+
+def _enrich_browser(info: ForegroundInfo) -> ForegroundInfo:
+    """If ``info`` describes a focused browser, attach URL + page title.
+
+    The UIA lookup is wrapped in its own try/except so a failure here can't
+    take down the rest of the foreground probe.
+    """
+    try:
+        from . import browser_url_service as bus
+    except Exception as e:
+        logger.debug("browser_url_service unavailable: %s", e)
+        return info
+
+    if not info.available or not bus.is_browser_process(info.process_name):
+        return info
+
+    try:
+        page = bus.get_browser_page(
+            hwnd=info.window_handle,
+            process_name=info.process_name,
+            window_title=info.window_title,
+        )
+    except Exception as e:
+        logger.debug("Browser URL enrichment failed: %s", e)
+        return info
+
+    # ``dataclasses.replace`` keeps the frozen-dataclass contract.
+    from dataclasses import replace
+    return replace(
+        info,
+        is_browser=True,
+        browser_url=page.url,
+        browser_page_title=page.page_title,
+    )
+
+
+def _probe() -> ForegroundInfo:
+    system = platform.system()
+    try:
+        if system == "Windows":
+            info = _probe_windows()
+        elif system == "Darwin":
+            info = _probe_macos()
+        elif system == "Linux":
+            info = _probe_linux()
+        else:
+            return ForegroundInfo(
+                available=False, error=f"unsupported platform: {system}"
+            )
+        return _enrich_browser(info)
+    except Exception as e:
+        logger.warning("Foreground probe crashed: %s", e)
+        return ForegroundInfo(available=False, error=str(e))
+
+
+def get_foreground_info(force_refresh: bool = False) -> ForegroundInfo:
+    """Return the current foreground window/process snapshot.
+
+    Args:
+        force_refresh: bypass the short TTL cache. WebSocket broadcast loop
+            should leave this False; the REST endpoint accepts ?refresh=1
+            for callers that want a fresh probe.
+    """
+    if force_refresh:
+        _cache.invalidate()
+    return _cache.get(_CACHE_TTL, _probe)
+
+
+def reset_cache() -> None:
+    """Reset the cache. Useful in tests."""
+    _cache.invalidate()

media_server/services/websocket_manager.py

@@ -19,6 +19,9 @@ class ConnectionManager:
         self._active_connections: set[WebSocket] = set()
         self._lock = asyncio.Lock()
         self._last_status: dict[str, Any] | None = None
+        self._last_foreground: dict[str, Any] | None = None
+        self._foreground_poll_interval: float = 1.0
+        self._last_foreground_poll: float = 0.0
         self._get_status_func: Callable[[], Coroutine[Any, Any, Any]] | None = None
         self._broadcast_task: asyncio.Task | None = None
         self._poll_interval: float = 0.5  # Internal poll interval for change detection
@@ -54,6 +57,18 @@ class ConnectionManager:
             except Exception as e:
                 logger.debug("Failed to send initial status: %s", e)
 
+        # Push a fresh foreground snapshot on connect so the UI can render
+        # the tile immediately instead of waiting for the next change.
+        try:
+            from .foreground_service import get_foreground_info
+
+            fg = await asyncio.to_thread(get_foreground_info)
+            fg_dict = fg.to_dict()
+            self._last_foreground = fg_dict
+            await websocket.send_json({"type": "foreground", "data": fg_dict})
+        except Exception as e:
+            logger.debug("Failed to send initial foreground snapshot: %s", e)
+
     async def disconnect(self, websocket: WebSocket) -> None:
         """Remove a WebSocket connection. Stops audio capture if last visualizer subscriber."""
         should_stop = False
@@ -115,6 +130,35 @@ class ConnectionManager:
         await self.broadcast(message)
         logger.info("Broadcast sent: links_changed")
 
+    def foreground_changed(
+        self, old: dict[str, Any] | None, new: dict[str, Any]
+    ) -> bool:
+        """Detect a meaningful change in the foreground process snapshot.
+
+        The probe also returns ``window_geometry`` which jitters on every
+        pixel of cursor drag — comparing the whole dict would flood clients.
+        We only diff the fields a user (or HA automation) would actually act
+        on. ``window_geometry``/``monitor_geometry``/``started_at`` are still
+        delivered in the payload, but they don't drive broadcast cadence.
+        """
+        if old is None:
+            return True
+        diff_fields = (
+            "pid",
+            "process_name",
+            "executable_path",
+            "window_title",
+            "is_fullscreen",
+            "is_minimized",
+            "monitor_id",
+            "available",
+            "error",
+        )
+        for f in diff_fields:
+            if old.get(f) != new.get(f):
+                return True
+        return False
+
     async def subscribe_visualizer(self, websocket: WebSocket) -> None:
         """Subscribe a client to audio visualizer data. Starts capture on first subscriber."""
         should_start = False
@@ -314,6 +358,10 @@ class ConnectionManager:
         get_status_func: Callable[[], Coroutine[Any, Any, Any]],
     ) -> None:
         """Background loop that polls for status changes and broadcasts."""
+        # Foreground tracker is imported lazily so unit tests of the WS
+        # manager don't drag in platform-specific probe code.
+        from .foreground_service import get_foreground_info
+
         while self._running:
             try:
                 # Only poll if we have connected clients
@@ -340,6 +388,28 @@ class ConnectionManager:
                     # Update cached status even without broadcast
                     self._last_status = status_dict
 
+                # Foreground process — poll at a coarser interval than media
+                # status. Broadcasts only fire on a real change, so a quiet
+                # desktop costs nothing.
+                now = time.time()
+                if (
+                    now - self._last_foreground_poll
+                ) >= self._foreground_poll_interval:
+                    self._last_foreground_poll = now
+                    try:
+                        fg = await asyncio.to_thread(get_foreground_info)
+                        fg_dict = fg.to_dict()
+                        if self.foreground_changed(self._last_foreground, fg_dict):
+                            self._last_foreground = fg_dict
+                            await self.broadcast(
+                                {"type": "foreground_update", "data": fg_dict}
+                            )
+                            logger.debug("Broadcast sent: foreground change")
+                        else:
+                            self._last_foreground = fg_dict
+                    except Exception as e:
+                        logger.debug("Foreground poll failed: %s", e)
+
                 await asyncio.sleep(self._poll_interval)
 
             except asyncio.CancelledError:

media_server/static/css/styles.css

@@ -9321,3 +9321,321 @@ body.is-fullscreen-player .now-playing .vu-meter {
     body.is-fullscreen-player .fs-bloom #fs-bloom-art { animation: none !important; }
     :root[data-theme="light"] body.is-fullscreen-player .fs-bloom { opacity: 0.22; }
 }
+
+/* ════════════════════════════════════════════════════════════════
+   FOREGROUND container — editorial process plate
+   ════════════════════════════════════════════════════════════════ */
+.foreground-container {
+    background: transparent;
+    border: 0;
+    padding: 0;
+    box-shadow: none;
+    margin-top: 28px;
+}
+
+.foreground-stage {
+    min-height: 360px;
+}
+
+/* Match the inter-section gap used between .settings-section blocks
+   in the Settings tab — keeps cadence consistent across tabs. */
+.display-container > * + * {
+    margin-top: 16px;
+}
+
+.foreground-card {
+    position: relative;
+    display: block;
+    padding: clamp(24px, 3vw, 40px) clamp(24px, 3vw, 40px) 28px;
+    border: 1px solid var(--rule);
+    border-top: 2px solid var(--copper);
+    background:
+        radial-gradient(120% 80% at 0% 0%, rgba(var(--copper-rgb), 0.05), transparent 60%),
+        var(--bg-paper);
+    box-shadow:
+        0 1px 0 var(--bg-paper),
+        0 28px 60px -28px rgba(0, 0, 0, 0.45),
+        0 8px 20px -10px rgba(0, 0, 0, 0.25);
+}
+.foreground-card[data-fullscreen="1"] {
+    border-top-color: var(--copper-hi);
+    box-shadow:
+        0 1px 0 var(--bg-paper),
+        0 28px 60px -28px rgba(0, 0, 0, 0.55),
+        0 0 0 1px rgba(var(--copper-rgb), 0.18),
+        0 0 60px -12px var(--copper-glow);
+}
+
+.foreground-card .fg-kicker {
+    display: flex;
+    align-items: center;
+    gap: 14px;
+    font-family: var(--mono);
+    font-size: 10px;
+    letter-spacing: 0.32em;
+    text-transform: uppercase;
+    color: var(--copper);
+    margin-bottom: 22px;
+}
+.foreground-card .fg-kicker::before,
+.foreground-card .fg-kicker::after {
+    content: "";
+    height: 1px;
+    background: var(--copper);
+    opacity: 0.6;
+    flex: 0 0 24px;
+}
+.foreground-card .fg-kicker::after { flex: 1 0 auto; }
+
+.foreground-card .fg-process {
+    font-family: var(--serif);
+    font-weight: 400;
+    font-size: clamp(34px, 4.4vw, 56px);
+    line-height: 1.02;
+    letter-spacing: -0.02em;
+    font-variation-settings: 'opsz' 144;
+    color: var(--ink);
+    margin: 0 0 10px;
+    word-break: break-word;
+    overflow-wrap: anywhere;
+    transition: color 180ms var(--ease, ease);
+}
+.foreground-card .fg-process:hover {
+    color: var(--copper-hi);
+}
+
+.foreground-card .fg-window-title {
+    font-family: var(--serif);
+    font-style: italic;
+    font-size: 20px;
+    font-weight: 300;
+    color: var(--ink-soft);
+    font-variation-settings: 'opsz' 60;
+    margin-bottom: 22px;
+    line-height: 1.35;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    display: -webkit-box;
+    -webkit-line-clamp: 2;
+    line-clamp: 2;
+    -webkit-box-orient: vertical;
+    word-break: break-word;
+}
+.foreground-card .fg-window-title:empty { display: none; }
+
+.foreground-card .fg-chips {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin-bottom: 28px;
+}
+.foreground-card .fg-chips:empty { display: none; }
+
+.fg-chip {
+    display: inline-flex;
+    align-items: center;
+    padding: 5px 11px;
+    font-family: var(--mono);
+    font-size: 10px;
+    letter-spacing: 0.18em;
+    text-transform: uppercase;
+    color: var(--ink-soft);
+    background: transparent;
+    border: 1px solid var(--rule-strong);
+    border-radius: 999px;
+    line-height: 1.2;
+    white-space: nowrap;
+}
+.fg-chip.fg-chip-accent {
+    color: var(--copper);
+    border-color: var(--copper);
+    background: rgba(var(--copper-rgb), 0.07);
+}
+.fg-chip.fg-chip-mute {
+    color: var(--ink-mute);
+    border-color: var(--rule);
+}
+
+.foreground-card .fg-details {
+    display: block;
+    margin: 0;
+    border-top: 1px solid var(--rule);
+}
+.foreground-card .fg-row {
+    display: grid;
+    grid-template-columns: minmax(160px, 220px) 1fr;
+    gap: 24px;
+    padding: 14px 0;
+    border-bottom: 1px solid var(--rule);
+    align-items: baseline;
+    min-width: 0;
+}
+.foreground-card .fg-row dt {
+    font-family: var(--mono);
+    font-size: 9px;
+    letter-spacing: 0.22em;
+    text-transform: uppercase;
+    color: var(--copper);
+    margin: 0;
+}
+.foreground-card .fg-row dd {
+    font-family: var(--serif);
+    font-style: italic;
+    font-size: 18px;
+    color: var(--ink);
+    font-variation-settings: 'opsz' 30;
+    margin: 0;
+    min-width: 0;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+.foreground-card .fg-mono {
+    font-family: var(--mono);
+    font-style: normal;
+    font-size: 13px;
+    letter-spacing: 0.02em;
+    color: var(--ink-soft);
+    font-variant-numeric: tabular-nums;
+    word-break: break-all;
+}
+
+.foreground-empty {
+    padding: 60px 24px;
+    text-align: center;
+    color: var(--ink-mute);
+}
+.foreground-empty svg {
+    width: 64px;
+    height: 64px;
+    margin-bottom: 14px;
+    opacity: 0.55;
+    color: var(--ink-faint);
+}
+.foreground-empty p {
+    font-family: var(--serif);
+    font-style: italic;
+    font-size: 18px;
+    color: var(--ink-soft);
+    margin: 0;
+}
+.foreground-empty .foreground-empty-error {
+    margin-top: 10px;
+    font-family: var(--mono);
+    font-style: normal;
+    font-size: 11px;
+    letter-spacing: 0.06em;
+    color: var(--ink-mute);
+    word-break: break-word;
+}
+
+/* ─── Header status badge ──────────────────────────────────── */
+.foreground-status-badge {
+    display: inline-flex;
+    align-items: center;
+    gap: 8px;
+    height: 32px;
+    padding: 0 12px 0 10px;
+    margin-right: 4px;
+    background: transparent;
+    border: 1px solid var(--rule-strong);
+    border-radius: 999px;
+    color: var(--ink-soft);
+    font-family: var(--mono);
+    font-size: 11px;
+    letter-spacing: 0.04em;
+    cursor: pointer;
+    max-width: 240px;
+    transition: color 180ms ease, border-color 180ms ease, background 180ms ease;
+}
+.foreground-status-badge:hover {
+    color: var(--ink);
+    border-color: var(--copper);
+    background: rgba(var(--copper-rgb), 0.06);
+}
+.foreground-status-badge.hidden { display: none !important; }
+
+.foreground-status-badge .fg-badge-mark {
+    width: 6px;
+    height: 6px;
+    border-radius: 50%;
+    background: var(--ink-mute);
+    flex-shrink: 0;
+}
+.foreground-status-badge.is-media .fg-badge-mark,
+.foreground-status-badge.is-fullscreen .fg-badge-mark {
+    background: var(--copper);
+    box-shadow: 0 0 8px var(--copper-glow);
+}
+.foreground-status-badge.is-fullscreen {
+    border-color: var(--copper);
+    color: var(--ink);
+}
+
+.foreground-status-badge .fg-badge-name {
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+    max-width: 140px;
+}
+.foreground-status-badge .fg-badge-tag {
+    color: var(--copper);
+    text-transform: uppercase;
+    letter-spacing: 0.14em;
+    font-size: 10px;
+    flex-shrink: 0;
+}
+.foreground-status-badge .fg-badge-tag.hidden { display: none; }
+
+/* ─── Light theme overrides ──────────────────────────────── */
+:root[data-theme="light"] .foreground-card {
+    background:
+        radial-gradient(120% 80% at 0% 0%, rgba(var(--copper-rgb), 0.05), transparent 60%),
+        var(--bg-paper);
+    box-shadow:
+        0 1px 0 var(--bg-paper),
+        0 22px 50px -24px rgba(26, 23, 21, 0.20),
+        0 6px 16px -8px rgba(26, 23, 21, 0.12);
+}
+:root[data-theme="light"] .foreground-card[data-fullscreen="1"] {
+    box-shadow:
+        0 1px 0 var(--bg-paper),
+        0 22px 50px -24px rgba(26, 23, 21, 0.28),
+        0 0 0 1px rgba(var(--copper-rgb), 0.20),
+        0 0 50px -12px var(--copper-glow);
+}
+:root[data-theme="light"] .foreground-status-badge {
+    border-color: rgba(26, 23, 21, 0.18);
+}
+:root[data-theme="light"] .foreground-status-badge:hover {
+    background: rgba(var(--copper-rgb), 0.08);
+}
+
+/* ─── Mobile breakpoint ──────────────────────────────────── */
+@media (max-width: 720px) {
+    .foreground-card {
+        padding: 22px 18px 20px;
+    }
+    .foreground-card .fg-process {
+        font-size: 30px;
+    }
+    .foreground-card .fg-window-title {
+        font-size: 16px;
+    }
+    .foreground-card .fg-row {
+        grid-template-columns: 1fr;
+        gap: 4px;
+        padding: 12px 0;
+    }
+    .foreground-card .fg-row dd {
+        font-size: 16px;
+    }
+    .foreground-status-badge {
+        max-width: 160px;
+    }
+    .foreground-status-badge .fg-badge-name {
+        max-width: 80px;
+    }
+    .foreground-status-badge .fg-badge-tag {
+        display: none;
+    }
+}

media_server/static/index.html

@@ -535,7 +535,7 @@
             </details>
         </div>
 
-        <!-- Display Control Section -->
+        <!-- Display Control Section (monitors first, foreground overview below) -->
         <div class="display-container" data-tab-content="display" role="tabpanel" id="panel-display">
             <div class="display-monitors" id="displayMonitors">
                 <div class="empty-state-illustration">
@@ -543,6 +543,12 @@
                     <p data-i18n="display.loading">Loading monitors...</p>
                 </div>
             </div>
+            <div class="foreground-stage" id="foregroundStage">
+                <div class="empty-state-illustration">
+                    <svg viewBox="0 0 64 64"><rect x="6" y="12" width="52" height="36" rx="3" fill="none" stroke="currentColor" stroke-width="2"/><line x1="6" y1="20" x2="58" y2="20" stroke="currentColor" stroke-width="2"/><circle cx="11" cy="16" r="1.4" fill="currentColor"/><circle cx="15" cy="16" r="1.4" fill="currentColor"/><circle cx="19" cy="16" r="1.4" fill="currentColor"/></svg>
+                    <p data-i18n="foreground.loading">Waiting for foreground signal…</p>
+                </div>
+            </div>
         </div>
     </div>
 

media_server/static/js/app.js

@@ -74,6 +74,10 @@ import {
     toggleDynamicBackground, applyDynamicBackground, updateBackgroundColors,
 } from './background.js';
 
+import {
+    updateForegroundUI, loadForegroundProcess,
+} from './foreground.js';
+
 // ============================================================
 // Register late-bound callbacks for core's updateAllText()
 // ============================================================
@@ -136,6 +140,8 @@ Object.assign(window, {
     onAudioDeviceChanged,
     // About
     showAboutDialog, closeAboutDialog,
+    // Foreground
+    loadForegroundProcess,
 });
 
 // ============================================================

media_server/static/js/foreground.js

@@ -0,0 +1,188 @@
+// ============================================================
+// Foreground: Currently-focused desktop process card (rendered at
+// the top of the Display tab)
+// ============================================================
+
+import { t } from './core.js';
+
+let latestForeground = null;
+let agoTickTimer = null;
+
+function escapeHtml(s) {
+    if (s === null || s === undefined) return '';
+    return String(s)
+        .replace(/&/g, '&')
+        .replace(/</g, '&lt;')
+        .replace(/>/g, '&gt;')
+        .replace(/"/g, '&quot;')
+        .replace(/'/g, '&#39;');
+}
+
+function formatAgo(epoch) {
+    if (!epoch) return '';
+    const now = Date.now() / 1000;
+    const diff = Math.max(0, now - epoch);
+    if (diff < 60) {
+        return t('foreground.ago.seconds', { n: Math.floor(diff) });
+    }
+    if (diff < 3600) {
+        return t('foreground.ago.minutes', { n: Math.floor(diff / 60) });
+    }
+    if (diff < 86400) {
+        const h = Math.floor(diff / 3600);
+        const m = Math.floor((diff % 3600) / 60);
+        return t('foreground.ago.hours', { n: h, m: m });
+    }
+    return t('foreground.ago.days', { n: Math.floor(diff / 86400) });
+}
+
+function formatGeometry(g) {
+    if (!g) return '—';
+    const w = g.width ?? (g.right - g.left);
+    const h = g.height ?? (g.bottom - g.top);
+    return `${w}×${h} @ (${g.left}, ${g.top})`;
+}
+
+function truncatePath(p, max = 64) {
+    if (!p) return '';
+    if (p.length <= max) return p;
+    // Keep the tail (filename) visible — that's the part the user cares about.
+    return '…' + p.slice(-(max - 1));
+}
+
+function renderEmpty(message, errorMsg) {
+    const stage = document.getElementById('foregroundStage');
+    if (!stage) return;
+    stage.innerHTML = `
+        <div class="empty-state-illustration foreground-empty">
+            <svg viewBox="0 0 64 64"><rect x="6" y="12" width="52" height="36" rx="3" fill="none" stroke="currentColor" stroke-width="2"/><line x1="6" y1="20" x2="58" y2="20" stroke="currentColor" stroke-width="2"/><circle cx="11" cy="16" r="1.4" fill="currentColor"/><circle cx="15" cy="16" r="1.4" fill="currentColor"/><circle cx="19" cy="16" r="1.4" fill="currentColor"/></svg>
+            <p>${escapeHtml(message)}</p>
+            ${errorMsg ? `<p class="foreground-empty-error">${escapeHtml(errorMsg)}</p>` : ''}
+        </div>
+    `;
+}
+
+function renderTile(data) {
+    const stage = document.getElementById('foregroundStage');
+    if (!stage) return;
+
+    const procName = data.process_name || '—';
+    const winTitle = data.window_title || '';
+    const execPath = data.executable_path || '';
+    const pid = data.pid ?? '—';
+    const startedEpoch = data.started_at;
+    const startedAgo = startedEpoch ? formatAgo(startedEpoch) : '—';
+    const startedAbs = startedEpoch
+        ? new Date(startedEpoch * 1000).toLocaleString()
+        : '';
+    const geom = formatGeometry(data.window_geometry);
+    const platform = data.platform || '—';
+    const monitorId = data.monitor_id;
+
+    // Chips: only render ones that apply
+    const chips = [];
+    if (data.is_fullscreen) {
+        chips.push(`<span class="fg-chip fg-chip-accent">${escapeHtml(t('foreground.fullscreen'))}</span>`);
+    } else if (!data.is_minimized) {
+        chips.push(`<span class="fg-chip">${escapeHtml(t('foreground.windowed'))}</span>`);
+    }
+    if (data.is_minimized) {
+        chips.push(`<span class="fg-chip fg-chip-mute">${escapeHtml(t('foreground.minimized'))}</span>`);
+    }
+    if (monitorId !== null && monitorId !== undefined) {
+        chips.push(`<span class="fg-chip">${escapeHtml(t('foreground.monitor', { n: monitorId + 1 }))}</span>`);
+    }
+    if (data.is_browser) {
+        chips.push(`<span class="fg-chip fg-chip-mute">${escapeHtml(t('foreground.browser'))}</span>`);
+    }
+
+    // Optional browser-only detail rows (page title + URL when available)
+    const browserRows = [];
+    if (data.is_browser) {
+        if (data.browser_page_title) {
+            browserRows.push(`
+                <div class="fg-row">
+                    <dt>${escapeHtml(t('foreground.page_title'))}</dt>
+                    <dd title="${escapeHtml(data.browser_page_title)}">${escapeHtml(data.browser_page_title)}</dd>
+                </div>
+            `);
+        }
+        if (data.browser_url) {
+            browserRows.push(`
+                <div class="fg-row">
+                    <dt>${escapeHtml(t('foreground.url'))}</dt>
+                    <dd title="${escapeHtml(data.browser_url)}"><span class="fg-mono">${escapeHtml(truncatePath(data.browser_url, 80))}</span></dd>
+                </div>
+            `);
+        }
+    }
+
+    stage.innerHTML = `
+        <article class="foreground-card" data-fullscreen="${data.is_fullscreen ? '1' : '0'}">
+            <div class="fg-kicker">
+                <span data-i18n="foreground.kicker">Foreground</span>
+            </div>
+            <h1 class="fg-process" title="${escapeHtml(procName)}">${escapeHtml(procName)}</h1>
+            <div class="fg-window-title" title="${escapeHtml(winTitle)}">${escapeHtml(winTitle)}</div>
+
+            <div class="fg-chips">${chips.join('')}</div>
+
+            <dl class="fg-details">
+                ${browserRows.join('')}
+                <div class="fg-row">
+                    <dt>${escapeHtml(t('foreground.executable'))}</dt>
+                    <dd title="${escapeHtml(execPath)}"><span class="fg-mono">${escapeHtml(truncatePath(execPath))}</span></dd>
+                </div>
+                <div class="fg-row">
+                    <dt>${escapeHtml(t('foreground.pid'))}</dt>
+                    <dd><span class="fg-mono">${escapeHtml(String(pid))}</span></dd>
+                </div>
+                <div class="fg-row">
+                    <dt>${escapeHtml(t('foreground.started'))}</dt>
+                    <dd title="${escapeHtml(startedAbs)}"><span class="fg-ago" data-started="${startedEpoch ?? ''}">${escapeHtml(startedAgo)}</span></dd>
+                </div>
+                <div class="fg-row">
+                    <dt>${escapeHtml(t('foreground.geometry'))}</dt>
+                    <dd><span class="fg-mono">${escapeHtml(geom)}</span></dd>
+                </div>
+                <div class="fg-row">
+                    <dt>${escapeHtml(t('foreground.platform'))}</dt>
+                    <dd>${escapeHtml(platform)}</dd>
+                </div>
+            </dl>
+        </article>
+    `;
+}
+
+function startAgoTicker() {
+    if (agoTickTimer) return;
+    agoTickTimer = setInterval(() => {
+        const el = document.querySelector('.fg-ago[data-started]');
+        if (!el) return;
+        const epoch = parseFloat(el.getAttribute('data-started'));
+        if (!epoch) return;
+        el.textContent = formatAgo(epoch);
+    }, 15000);
+}
+
+export function updateForegroundUI(data) {
+    latestForeground = data;
+
+    if (!data || data.available === false) {
+        const errMsg = data && data.error ? data.error : '';
+        renderEmpty(t('foreground.unavailable'), errMsg);
+    } else if (!data.process_name && !data.pid) {
+        renderEmpty(t('foreground.no_process'), '');
+    } else {
+        renderTile(data);
+        startAgoTicker();
+    }
+}
+
+export function loadForegroundProcess() {
+    // Push-only — just render the cached state. If nothing has arrived
+    // yet, leave the loading placeholder visible.
+    if (latestForeground !== null) {
+        updateForegroundUI(latestForeground);
+    }
+}

media_server/static/js/player.js

@@ -13,6 +13,7 @@ import {
 } from './core.js';
 import { updateBackgroundColors } from './background.js';
 import { loadDisplayMonitors } from './links.js';
+import { loadForegroundProcess } from './foreground.js';
 import { IconSelect } from './icon-select.js';
 
 // Tab management
@@ -75,6 +76,7 @@ export function switchTab(tabName) {
 
     if (tabName === 'display') {
         loadDisplayMonitors();
+        loadForegroundProcess();
     }
 
     localStorage.setItem('activeTab', tabName);

media_server/static/js/websocket.js

@@ -12,6 +12,7 @@ import { updateUI, setFrequencyData, stopPositionInterpolation, loadAudioDevices
 import { loadScripts, loadScriptsTable, displayQuickAccess } from './scripts.js';
 import { loadCallbacksTable } from './callbacks.js';
 import { loadHeaderLinks, loadLinksTable } from './links.js';
+import { updateForegroundUI } from './foreground.js';
 
 let reconnectTimeout = null;
 let wsReconnectAttempts = 0;
@@ -118,6 +119,8 @@ export function connectWebSocket(token) {
 
         if (msg.type === 'status' || msg.type === 'status_update') {
             updateUI(msg.data);
+        } else if (msg.type === 'foreground' || msg.type === 'foreground_update') {
+            updateForegroundUI(msg.data);
         } else if (msg.type === 'scripts_changed') {
             console.log('Scripts changed, reloading...');
             loadScripts();

media_server/static/locales/en.json

@@ -292,5 +292,29 @@
   "about.source_code": "Source Code",
   "dialog.close": "Close",
   "update.available": "Update available: v{version}",
-  "update.view_release": "View Release"
+  "update.view_release": "View Release",
+  "tab.foreground": "Foreground",
+  "foreground.kicker": "Foreground",
+  "foreground.loading": "Waiting for foreground signal…",
+  "foreground.no_process": "No foreground process",
+  "foreground.unavailable": "Foreground tracking unavailable on this platform",
+  "foreground.process": "Process",
+  "foreground.window_title": "Window title",
+  "foreground.executable": "Executable",
+  "foreground.pid": "PID",
+  "foreground.monitor": "Monitor {n}",
+  "foreground.started": "Started",
+  "foreground.geometry": "Geometry",
+  "foreground.platform": "Platform",
+  "foreground.fullscreen": "Fullscreen",
+  "foreground.minimized": "Minimized",
+  "foreground.windowed": "Windowed",
+  "foreground.browser": "Browser",
+  "foreground.page_title": "Page title",
+  "foreground.url": "URL",
+  "foreground.badge.title": "View foreground process",
+  "foreground.ago.seconds": "{n}s ago",
+  "foreground.ago.minutes": "{n}m ago",
+  "foreground.ago.hours": "{n}h {m}m ago",
+  "foreground.ago.days": "{n}d ago"
 }

media_server/static/locales/ru.json

@@ -292,5 +292,29 @@
   "about.source_code": "Исходный код",
   "dialog.close": "Закрыть",
   "update.available": "Доступно обновление: v{version}",
-  "update.view_release": "Перейти к релизу"
+  "update.view_release": "Перейти к релизу",
+  "tab.foreground": "Активное окно",
+  "foreground.kicker": "Активное окно",
+  "foreground.loading": "Ожидание сигнала об активном окне…",
+  "foreground.no_process": "Активное окно не определено",
+  "foreground.unavailable": "Отслеживание активного окна недоступно",
+  "foreground.process": "Процесс",
+  "foreground.window_title": "Заголовок окна",
+  "foreground.executable": "Путь к программе",
+  "foreground.pid": "PID",
+  "foreground.monitor": "Монитор {n}",
+  "foreground.started": "Запущено",
+  "foreground.geometry": "Геометрия",
+  "foreground.platform": "Платформа",
+  "foreground.fullscreen": "Полноэкранный",
+  "foreground.minimized": "Свёрнут",
+  "foreground.windowed": "Оконный",
+  "foreground.browser": "Браузер",
+  "foreground.page_title": "Заголовок страницы",
+  "foreground.url": "URL",
+  "foreground.badge.title": "Открыть активное окно",
+  "foreground.ago.seconds": "{n} с назад",
+  "foreground.ago.minutes": "{n} мин назад",
+  "foreground.ago.hours": "{n} ч {m} мин назад",
+  "foreground.ago.days": "{n} дн назад"
 }

tests/test_foreground_service.py

@@ -0,0 +1,87 @@
+"""Smoke tests for the foreground tracker.
+
+The OS-specific probe code is hard to mock end-to-end inside a CI container,
+so these tests focus on the platform-agnostic surface: the dataclass shape,
+TTL caching, and graceful fallback when the platform probe raises. The
+Windows/Linux/macOS probes themselves are exercised through manual runs.
+"""
+
+from __future__ import annotations
+
+import time
+
+import pytest
+
+from media_server.services import foreground_service as fg
+
+
+def setup_function(_):
+    fg.reset_cache()
+
+
+def test_unavailable_default_shape():
+    info = fg.ForegroundInfo(available=False)
+    d = info.to_dict()
+    assert d["available"] is False
+    assert d["pid"] is None
+    assert d["process_name"] is None
+    assert d["is_fullscreen"] is False
+    assert "platform" in d
+
+
+def test_cache_returns_same_instance(monkeypatch):
+    calls = {"n": 0}
+
+    def fake_probe():
+        calls["n"] += 1
+        return fg.ForegroundInfo(available=True, pid=42, process_name="x.exe")
+
+    monkeypatch.setattr(fg, "_probe", fake_probe)
+
+    a = fg.get_foreground_info()
+    b = fg.get_foreground_info()
+    assert a is b
+    assert calls["n"] == 1
+
+
+def test_cache_force_refresh(monkeypatch):
+    calls = {"n": 0}
+
+    def fake_probe():
+        calls["n"] += 1
+        return fg.ForegroundInfo(available=True, pid=calls["n"])
+
+    monkeypatch.setattr(fg, "_probe", fake_probe)
+
+    fg.get_foreground_info()
+    fg.get_foreground_info(force_refresh=True)
+    assert calls["n"] == 2
+
+
+def test_cache_ttl_expiry(monkeypatch):
+    calls = {"n": 0}
+
+    def fake_probe():
+        calls["n"] += 1
+        return fg.ForegroundInfo(available=True, pid=calls["n"])
+
+    monkeypatch.setattr(fg, "_probe", fake_probe)
+    monkeypatch.setattr(fg, "_CACHE_TTL", 0.0)
+    # Re-bind the cache's TTL by exercising it twice with TTL 0.
+    fg.get_foreground_info()
+    fg.get_foreground_info()
+    assert calls["n"] == 2
+
+
+def test_probe_crash_returns_unavailable(monkeypatch):
+    def boom():
+        raise RuntimeError("kaboom")
+
+    # Force every platform branch to call our crashing probe.
+    monkeypatch.setattr(fg, "_probe_windows", boom)
+    monkeypatch.setattr(fg, "_probe_linux", boom)
+    monkeypatch.setattr(fg, "_probe_macos", boom)
+
+    info = fg._probe()
+    assert info.available is False
+    assert info.error and "kaboom" in info.error