fix(media): Circuit-Breaker für D-Bus-Connect-Fehler

Nach dem ersten fehlgeschlagenen Bus-Connect wird der Controller
dauerhaft deaktiviert, statt bei jedem Hotkey-Druck einen neuen
Connect-Versuch zu starten.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_media_mpris.py

@@ -173,3 +173,27 @@ async def test_pause_is_noop_when_bus_unreachable(monkeypatch, caplog):
     assert controller._paused == []
     assert any("D-Bus" in r.message or "bus" in r.message.lower()
                for r in caplog.records)
+
+
+@pytest.mark.asyncio
+async def test_pause_skips_reconnect_after_bus_failure(monkeypatch):
+    """Bus-Connect-Fehler darf nicht bei jedem Aufruf erneut versucht werden."""
+    from whisper_local.media._mpris import MprisController
+
+    connect_calls = 0
+
+    async def failing_connect(self):
+        nonlocal connect_calls
+        connect_calls += 1
+        raise RuntimeError("no session bus")
+
+    monkeypatch.setattr(
+        "dbus_next.aio.MessageBus.connect", failing_connect, raising=False
+    )
+    controller = MprisController()
+
+    await controller.pause()
+    await controller.pause()
+    await controller.pause()
+
+    assert connect_calls == 1

whisper_local/media/_mpris.py

@@ -18,8 +18,11 @@ class MprisController:
     def __init__(self) -> None:
         self._paused: list[str] = []
         self._bus: Any = None
+        self._bus_broken: bool = False
 
     async def _ensure_bus(self) -> Any:
+        if self._bus_broken:
+            raise RuntimeError("D-Bus session bus is unavailable")
         if self._bus is None:
             from dbus_next.aio import MessageBus
             self._bus = await MessageBus().connect()
@@ -65,7 +68,11 @@ class MprisController:
         try:
             names = await self._list_player_names()
         except Exception as e:
-            logger.warning("D-Bus nicht erreichbar, überspringe Media-Pause: %s", e)
+            if not self._bus_broken:
+                logger.warning(
+                    "D-Bus nicht erreichbar, Media-Pause dauerhaft deaktiviert: %s", e
+                )
+                self._bus_broken = True
             self._paused = []
             return
         results = await asyncio.gather(