Add database seeding functionality and enhance model relationships

- Implement initial data seeding for plans in the database.
- Create a new `seed_all_data` function to manage seeding process.
- Update `Sound` and `User` models to include relationships for `SoundPlayed` and `Stream`.

app/models/sound.py

@@ -6,6 +6,7 @@ from app.models.base import BaseModel
 
 if TYPE_CHECKING:
     from app.models.playlist_sound import PlaylistSound
+    from app.models.sound_played import SoundPlayed
     from app.models.stream import Stream
 
 
@@ -31,3 +32,4 @@ class Sound(BaseModel, table=True):
     # relationships
     playlist_sounds: list["PlaylistSound"] = Relationship(back_populates="sound")
     streams: list["Stream"] = Relationship(back_populates="sound")
+    play_history: list["SoundPlayed"] = Relationship(back_populates="sound")