feat: Implement playlist reordering with position swapping and reload player on current playlist changes

app/repositories/playlist.py

@@ -165,6 +165,20 @@ class PlaylistRepository(BaseRepository[Playlist]):
 
         """
         try:
+            # Phase 1: Set all positions to temporary negative values to avoid conflicts
+            temp_offset = -10000  # Use large negative number to avoid conflicts
+            for i, (sound_id, _) in enumerate(sound_positions):
+                statement = select(PlaylistSound).where(
+                    PlaylistSound.playlist_id == playlist_id,
+                    PlaylistSound.sound_id == sound_id,
+                )
+                result = await self.session.exec(statement)
+                playlist_sound = result.first()
+
+                if playlist_sound:
+                    playlist_sound.position = temp_offset + i
+
+            # Phase 2: Set the final positions
             for sound_id, new_position in sound_positions:
                 statement = select(PlaylistSound).where(
                     PlaylistSound.playlist_id == playlist_id,