sync(api): copy latest standalone code and merge alembic migrations

Co-Authored-By: Paperclip <noreply@paperclip.ing>

api/src/cartsnitch_api/services/alerts.py

@@ -4,6 +4,8 @@ Alerts are generated by StickerShock and ShrinkRay services and written to the D
 This service reads them for the API gateway.
 """
 
+from uuid import UUID
+
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
@@ -13,7 +15,7 @@ class AlertService:
     def __init__(self, db: AsyncSession) -> None:
         self.db = db
 
-    async def list_alerts(self, user_id: str) -> list[dict]:
+    async def list_alerts(self, user_id: UUID) -> list[dict]:
         """List shrinkflation events for products the user has purchased."""
         from cartsnitch_api.models import Purchase, PurchaseItem, ShrinkflationEvent
 
@@ -55,7 +57,7 @@ class AlertService:
             for e in events
         ]
 
-    async def get_settings(self, user_id: str) -> dict:
+    async def get_settings(self, user_id: UUID) -> dict:
         # Alert settings would be stored in a user_settings table.
         # For now, return defaults since the table doesn't exist yet in common lib.
         return {
@@ -64,7 +66,7 @@ class AlertService:
             "email_notifications": False,
         }
 
-    async def update_settings(self, user_id: str, **fields) -> dict:
+    async def update_settings(self, user_id: UUID, **fields) -> dict:
         # Would update user_settings table. Return merged defaults for now.
         current = await self.get_settings(user_id)
         for k, v in fields.items():