feat: Implement favorites management API; add endpoints for adding, removing, and retrieving favorites for sounds and playlists

feat: Create Favorite model and repository for managing user favorites in the database
feat: Add FavoriteService to handle business logic for favorites management
feat: Enhance Playlist and Sound response schemas to include favorite indicators and counts
refactor: Update API routes to include favorites functionality in playlists and sounds

app/schemas/sound.py

@@ -0,0 +1,95 @@
+"""Sound response schemas."""
+
+from datetime import datetime
+
+from pydantic import BaseModel, Field
+
+from app.models.sound import Sound
+
+
+class SoundResponse(BaseModel):
+    """Response schema for a sound with favorite indicator."""
+
+    id: int = Field(description="Sound ID")
+    type: str = Field(description="Sound type")
+    name: str = Field(description="Sound name")
+    filename: str = Field(description="Sound filename")
+    duration: int = Field(description="Duration in milliseconds")
+    size: int = Field(description="File size in bytes")
+    hash: str = Field(description="File hash")
+    normalized_filename: str | None = Field(
+        description="Normalized filename", default=None
+    )
+    normalized_duration: int | None = Field(
+        description="Normalized duration in milliseconds", default=None
+    )
+    normalized_size: int | None = Field(
+        description="Normalized file size in bytes", default=None
+    )
+    normalized_hash: str | None = Field(
+        description="Normalized file hash", default=None
+    )
+    thumbnail: str | None = Field(description="Thumbnail filename", default=None)
+    play_count: int = Field(description="Number of times played")
+    is_normalized: bool = Field(description="Whether the sound is normalized")
+    is_music: bool = Field(description="Whether the sound is music")
+    is_deletable: bool = Field(description="Whether the sound can be deleted")
+    is_favorited: bool = Field(
+        description="Whether the sound is favorited by the current user", default=False
+    )
+    favorite_count: int = Field(
+        description="Number of users who favorited this sound", default=0
+    )
+    created_at: datetime = Field(description="Creation timestamp")
+    updated_at: datetime = Field(description="Last update timestamp")
+
+    class Config:
+        """Pydantic config."""
+
+        from_attributes = True
+
+    @classmethod
+    def from_sound(
+        cls, sound: Sound, is_favorited: bool = False, favorite_count: int = 0
+    ) -> "SoundResponse":
+        """Create a SoundResponse from a Sound model.
+
+        Args:
+            sound: The Sound model
+            is_favorited: Whether the sound is favorited by the current user
+            favorite_count: Number of users who favorited this sound
+
+        Returns:
+            SoundResponse instance
+        """
+        if sound.id is None:
+            raise ValueError("Sound ID cannot be None")
+
+        return cls(
+            id=sound.id,
+            type=sound.type,
+            name=sound.name,
+            filename=sound.filename,
+            duration=sound.duration,
+            size=sound.size,
+            hash=sound.hash,
+            normalized_filename=sound.normalized_filename,
+            normalized_duration=sound.normalized_duration,
+            normalized_size=sound.normalized_size,
+            normalized_hash=sound.normalized_hash,
+            thumbnail=sound.thumbnail,
+            play_count=sound.play_count,
+            is_normalized=sound.is_normalized,
+            is_music=sound.is_music,
+            is_deletable=sound.is_deletable,
+            is_favorited=is_favorited,
+            favorite_count=favorite_count,
+            created_at=sound.created_at,
+            updated_at=sound.updated_at,
+        )
+
+
+class SoundsListResponse(BaseModel):
+    """Response schema for a list of sounds."""
+
+    sounds: list[SoundResponse] = Field(description="List of sounds")