Initial commit: Media server and Home Assistant integration

- FastAPI server for Windows media control via WinRT/SMTC
- Home Assistant custom integration with media player entity
- Script button entities for system commands
- Position tracking with grace period for track skip handling
- Server availability detection in HA entity

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

media_server/models/media.py

@@ -0,0 +1,61 @@
+"""Media-related Pydantic models."""
+
+from enum import Enum
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+class MediaState(str, Enum):
+    """Playback state enumeration."""
+
+    PLAYING = "playing"
+    PAUSED = "paused"
+    STOPPED = "stopped"
+    IDLE = "idle"
+
+
+class MediaInfo(BaseModel):
+    """Information about the currently playing media."""
+
+    title: Optional[str] = Field(None, description="Track/media title")
+    artist: Optional[str] = Field(None, description="Artist name")
+    album: Optional[str] = Field(None, description="Album name")
+    album_art_url: Optional[str] = Field(None, description="URL to album artwork")
+    duration: Optional[float] = Field(
+        None, description="Total duration in seconds", ge=0
+    )
+    position: Optional[float] = Field(
+        None, description="Current position in seconds", ge=0
+    )
+
+
+class MediaStatus(BaseModel):
+    """Complete media playback status."""
+
+    state: MediaState = Field(default=MediaState.IDLE, description="Playback state")
+    title: Optional[str] = Field(None, description="Track/media title")
+    artist: Optional[str] = Field(None, description="Artist name")
+    album: Optional[str] = Field(None, description="Album name")
+    album_art_url: Optional[str] = Field(None, description="URL to album artwork")
+    duration: Optional[float] = Field(
+        None, description="Total duration in seconds", ge=0
+    )
+    position: Optional[float] = Field(
+        None, description="Current position in seconds", ge=0
+    )
+    volume: int = Field(default=100, description="Volume level (0-100)", ge=0, le=100)
+    muted: bool = Field(default=False, description="Whether audio is muted")
+    source: Optional[str] = Field(None, description="Media source/player name")
+
+
+class VolumeRequest(BaseModel):
+    """Request model for setting volume."""
+
+    volume: int = Field(..., description="Volume level (0-100)", ge=0, le=100)
+
+
+class SeekRequest(BaseModel):
+    """Request model for seeking to a position."""
+
+    position: float = Field(..., description="Position in seconds to seek to", ge=0)