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/db/sqlite/migrations.py

@@ -0,0 +1,64 @@
+"""
+Reads and saves the latest database migrations version.
+"""
+
+
+from app.db.sqlite.utils import SQLiteManager
+
+
+class MigrationManager:
+    all_get_sql = "SELECT * FROM migrations"
+    pre_init_set_sql = "UPDATE migrations SET pre_init_version = ? WHERE id = 1"
+    post_init_set_sql = "UPDATE migrations SET post_init_version = ? WHERE id = 1"
+
+    @classmethod
+    def get_preinit_version(cls) -> int:
+        """
+        Returns the latest userdata pre-init database version.
+        """
+        with SQLiteManager() as cur:
+            cur.execute(cls.all_get_sql)
+            return int(cur.fetchone()[1])
+
+    @classmethod
+    def get_maindb_postinit_version(cls) -> int:
+        """
+        Returns the latest maindb post-init database version.
+        """
+        with SQLiteManager() as cur:
+            cur.execute(cls.all_get_sql)
+            return int(cur.fetchone()[2])
+
+    @classmethod
+    def get_userdatadb_postinit_version(cls) -> int:
+        """
+        Returns the latest userdata post-init database version.
+        """
+        with SQLiteManager(userdata_db=True) as cur:
+            cur.execute(cls.all_get_sql)
+            return cur.fetchone()[2]
+
+    # 👇 Setters 👇
+    @classmethod
+    def set_preinit_version(cls, version: int):
+        """
+        Sets the userdata pre-init database version.
+        """
+        with SQLiteManager() as cur:
+            cur.execute(cls.pre_init_set_sql, (version,))
+
+    @classmethod
+    def set_maindb_postinit_version(cls, version: int):
+        """
+        Sets the maindb post-init database version.
+        """
+        with SQLiteManager() as cur:
+            cur.execute(cls.post_init_set_sql, (version,))
+
+    @classmethod
+    def set_userdatadb_postinit_version(cls, version: int):
+        """
+        Sets the userdata post-init database version.
+        """
+        with SQLiteManager(userdata_db=True) as cur:
+            cur.execute(cls.post_init_set_sql, (version,))