fix: update database engine to async (fixes import error)

combine.py imports async_session_factory from engine.py but the
committed version only had sync Session. Update to the async
implementation needed by the passkey feature.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: EstrellaXD

backend/src/module/database/engine.py

@@ -1,7 +1,32 @@
-from sqlmodel import Session, create_engine
+from sqlalchemy import event
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.pool import StaticPool
 
 from module.conf import DATA_PATH
 
-engine = create_engine(DATA_PATH)
+# Convert sqlite:///path to sqlite+aiosqlite:///path for async support
+ASYNC_DATA_PATH = DATA_PATH.replace("sqlite:///", "sqlite+aiosqlite:///")
 
-db_session = Session(engine)
+engine = create_async_engine(
+    ASYNC_DATA_PATH,
+    echo=False,
+    poolclass=StaticPool,
+    connect_args={"check_same_thread": False},
+)
+
+
+@event.listens_for(engine.sync_engine, "connect")
+def _set_sqlite_pragma(dbapi_connection, connection_record):
+    cursor = dbapi_connection.cursor()
+    cursor.execute("PRAGMA journal_mode=WAL")
+    cursor.execute("PRAGMA synchronous=NORMAL")
+    cursor.execute("PRAGMA cache_size=-64000")  # 64MB
+    cursor.execute("PRAGMA busy_timeout=5000")
+    cursor.execute("PRAGMA foreign_keys=ON")
+    cursor.close()
+
+
+async_session_factory = sessionmaker(
+    engine, class_=AsyncSession, expire_on_commit=False
+)