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/artistlib.py

@@ -79,7 +79,7 @@ class CheckArtistImages:
                 tqdm(
                     pool.map(self.download_image, artist_store.ArtistStore.artists),
                     total=len(artist_store.ArtistStore.artists),
-                    desc="Downloading artist images",
+                    desc="Downloading missing artist images",
                 )
             )