feat: sqlite migration runner with meta version table

chat/db/connection.py

@@ -0,0 +1,17 @@
+from __future__ import annotations
+import sqlite3
+from contextlib import contextmanager
+from pathlib import Path
+
+
+@contextmanager
+def open_db(path: Path):
+    path.parent.mkdir(parents=True, exist_ok=True)
+    conn = sqlite3.connect(path)
+    conn.execute("PRAGMA journal_mode=WAL")
+    conn.execute("PRAGMA foreign_keys=ON")
+    try:
+        yield conn
+        conn.commit()
+    finally:
+        conn.close()