feat: Implement sound normalization service and API endpoints

- Added SoundNormalizerService for normalizing audio files with support for one-pass and two-pass normalization methods.
- Introduced API endpoints for normalizing all sounds and specific sounds by ID, including support for force normalization and handling of already normalized sounds.
- Created comprehensive test suite for the sound normalizer service and its API endpoints, covering various scenarios including success, errors, and edge cases.
- Refactored sound scanning service to utilize SHA-256 for file hashing instead of MD5 for improved security.
- Enhanced logging and error handling throughout the sound normalization process.

app/repositories/sound.py

@@ -126,3 +126,26 @@ class SoundRepository:
         except Exception:
             logger.exception("Failed to get popular sounds")
             raise
+
+    async def get_unnormalized_sounds(self) -> list[Sound]:
+        """Get all sounds that haven't been normalized yet."""
+        try:
+            statement = select(Sound).where(Sound.is_normalized == False)  # noqa: E712
+            result = await self.session.exec(statement)
+            return list(result.all())
+        except Exception:
+            logger.exception("Failed to get unnormalized sounds")
+            raise
+
+    async def get_unnormalized_sounds_by_type(self, sound_type: str) -> list[Sound]:
+        """Get unnormalized sounds by type."""
+        try:
+            statement = select(Sound).where(
+                Sound.type == sound_type,
+                Sound.is_normalized == False,  # noqa: E712
+            )
+            result = await self.session.exec(statement)
+            return list(result.all())
+        except Exception:
+            logger.exception("Failed to get unnormalized sounds by type: %s", sound_type)
+            raise