fix: prestart.sh uses get_session_factory instead of non-existent async_session_factory

prestart.sh

@@ -111,14 +111,15 @@ echo "[prestart] Auto-installing and activating discovered plugins..."
 python3 -c "
 import asyncio
 from app.plugins.registry import get_registry
-from app.core.db import async_session_factory
+from app.core.db import get_session_factory
 from sqlalchemy import select
 from app.models.plugin import Plugin as PluginModel
 
 async def auto_activate_plugins():
     r = get_registry()
     discovered = r.discover_builtins()
-    async with async_session_factory() as db:
+    factory = get_session_factory()
+    async with factory() as db:
         for name in discovered:
             result = await db.execute(select(PluginModel).where(PluginModel.name == name))
             record = result.scalar_one_or_none()