enable sqlite WAL mode

.gitignore

@@ -12,6 +12,8 @@ dist/
 # Development 
 .notes
 .*keys.db
+*.db-shm
+*.db-wal
 .*wallet.sqlite3
 *models.json
 .cashu

routstr/core/db.py

@@ -79,6 +79,8 @@ async def balances_for_mint_and_unit(
 async def init_db() -> None:
     """Initializes the database and creates tables if they don't exist."""
     async with engine.begin() as conn:
+        if DATABASE_URL.startswith("sqlite"):
+            await conn.exec_driver_sql("PRAGMA journal_mode=WAL")
         await conn.run_sync(SQLModel.metadata.create_all)