feat: add migration to move old files to xdg directory

+ add db column for migration version
+ handle pre-init migrations
+ handle post-init migration

app/migrations/__init__.py

@@ -2,19 +2,43 @@
 Migrations module.
 
 Reads and applies the latest database migrations.
+
+PLEASE NOTE: OLDER MIGRATIONS CAN NEVER BE DELETED.
+ONLY MODIFY OLD MIGRATIONS FOR BUG FIXES OR ENHANCEMENTS ONLY
+[TRY NOT TO MODIFY BEHAVIOR, UNLESS YOU KNOW WHAT YOU'RE DOING].
 """
+
+
+from app.db.sqlite.migrations import MigrationManager
+from app.logger import log
+
 from .main import main_db_migrations
 from .userdata import userdata_db_migrations
 
 
 def apply_migrations():
-    userdb_version = 0
-    maindb_version = 0
+    """
+    Applies the latest database migrations.
+    """
+
+    userdb_version = MigrationManager.get_userdatadb_postinit_version()
+    maindb_version = MigrationManager.get_maindb_postinit_version()
 
     for migration in main_db_migrations:
         if migration.version > maindb_version:
+            log.info("Running new MAIN-DB post-init migration: %s", migration.name)
             migration.migrate()
 
     for migration in userdata_db_migrations:
         if migration.version > userdb_version:
+            log.info("Running new USERDATA-DB post-init migration: %s", migration.name)
             migration.migrate()
+
+
+def set_postinit_migration_versions():
+    """
+    Sets the post-init migration versions.
+    """
+    # TODO: Don't forget to remove the zeros below when you add a valid migration 👇.
+    MigrationManager.set_maindb_postinit_version(0)
+    MigrationManager.set_userdatadb_postinit_version(0)