prevent running migrations if is_fresh_install

+ fix: sqlite3.ProgrammingError: Cannot operate on a closed cursor on ProcessAlbumColors()
+ move processing artist images from periodic_scans to Populate
+ bump hash string limit from 7 to 10
+ add last_mod property to database
+ fix: TypeError: '<' not supported between instances of 'int' and 'str' on album page

app/lib/trackslib.py

@@ -16,4 +16,4 @@ def validate_tracks() -> None:
     for track in tqdm(TrackStore.tracks, desc="Checking for deleted tracks"):
         if not os.path.exists(track.filepath):
             TrackStore.tracks.remove(track)
-            tdb.remove_track_by_filepath(track.filepath)
+            tdb.remove_tracks_by_filepaths(track.filepath)