feat: Add mute and unmute functionality to player service and API

app/services/player.py

@@ -47,6 +47,7 @@ class PlayerState:
         self.status: PlayerStatus = PlayerStatus.STOPPED
         self.mode: PlayerMode = PlayerMode.CONTINUOUS
         self.volume: int = 50
+        self.previous_volume: int = 50
         self.current_sound_id: int | None = None
         self.current_sound_index: int | None = None
         self.current_sound_position: int = 0
@@ -64,6 +65,7 @@ class PlayerState:
             "status": self.status.value,
             "mode": self.mode.value,
             "volume": self.volume,
+            "previous_volume": self.previous_volume,
             "position": self.current_sound_position or 0,
             "duration": self.current_sound_duration,
             "index": self.current_sound_index,
@@ -378,12 +380,27 @@ class PlayerService:
     async def set_volume(self, volume: int) -> None:
         """Set playback volume (0-100)."""
         volume = max(0, min(100, volume))  # Clamp to valid range
+        
+        # Store previous volume when muting (going from >0 to 0)
+        if self.state.volume > 0 and volume == 0:
+            self.state.previous_volume = self.state.volume
+            
         self.state.volume = volume
         self._player.audio_set_volume(volume)
 
         await self._broadcast_state()
         logger.debug("Volume set to: %s", volume)
 
+    async def mute(self) -> None:
+        """Mute the player (stores current volume as previous_volume)."""
+        if self.state.volume > 0:
+            await self.set_volume(0)
+
+    async def unmute(self) -> None:
+        """Unmute the player (restores previous_volume)."""
+        if self.state.volume == 0 and self.state.previous_volume > 0:
+            await self.set_volume(self.state.previous_volume)
+
     async def set_mode(self, mode: PlayerMode) -> None:
         """Set playback mode."""
         self.state.mode = mode