feat: Implement Text-to-Speech (TTS) functionality with API endpoints, models, and service integration

app/models/__init__.py

@@ -12,6 +12,7 @@ from .playlist_sound import PlaylistSound
 from .scheduled_task import ScheduledTask
 from .sound import Sound
 from .sound_played import SoundPlayed
+from .tts import TTS
 from .user import User
 from .user_oauth import UserOauth
 
@@ -27,6 +28,7 @@ __all__ = [
     "ScheduledTask",
     "Sound",
     "SoundPlayed",
+    "TTS",
     "User",
     "UserOauth",
 ]