Harden SQLite connection defaults with WAL and busy timeout

backend/app/db.py

@@ -106,6 +106,13 @@ _SCHEMA_STATEMENTS: list[str] = [
 # ---------------------------------------------------------------------------
 
 
+async def _configure_connection(db: aiosqlite.Connection) -> None:
+    """Apply hardening pragmas to a newly-opened SQLite connection."""
+    await db.execute("PRAGMA journal_mode=WAL;")
+    await db.execute("PRAGMA foreign_keys=ON;")
+    await db.execute("PRAGMA busy_timeout=5000;")
+
+
 async def init_db(db: aiosqlite.Connection) -> None:
     """Create all BanGUI application tables if they do not already exist.
 
@@ -117,10 +124,7 @@ async def init_db(db: aiosqlite.Connection) -> None:
         db: An open :class:`aiosqlite.Connection` to the application database.
     """
     log.info("initialising_database_schema")
-    async with db.execute("PRAGMA journal_mode=WAL;"):
-        pass
-    async with db.execute("PRAGMA foreign_keys=ON;"):
-        pass
+    await _configure_connection(db)
     for statement in _SCHEMA_STATEMENTS:
         await db.executescript(statement)
     await db.commit()
@@ -138,5 +142,5 @@ async def open_db(database_path: str) -> aiosqlite.Connection:
     """
     db = await aiosqlite.connect(database_path)
     db.row_factory = aiosqlite.Row
-    await db.execute("PRAGMA foreign_keys=ON;")
+    await _configure_connection(db)
     return db