feat: add subscription and transaction repositories

- Implemented SubscriptionRepository with methods to get, create, and update subscriptions.
- Added BalanceTXRepository for creating and retrieving balance transactions.
- Introduced a test script for simulating Pally webhook for local testing.

repositories/bills.py

@@ -1,7 +1,7 @@
-from sqlalchemy import select
+from sqlalchemy import select, update
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from db.models.bills import Bill, BillStatus
+from db.models.bills import Bill, DepositStatus
 
 
 class BillsRepository:
@@ -17,9 +17,15 @@ class BillsRepository:
         *,
         creator_id: int,
         amount: int,
-        status: BillStatus | None = BillStatus.NEW,
+        status: DepositStatus | None = DepositStatus.PENDING,
     ) -> Bill:
         bill = Bill(creator_id=creator_id, amount=amount, status=status)
         session.add(bill)
         await session.commit()
         return bill
+
+    async def update_bill_status(self, session: AsyncSession, bill_id: int, status: DepositStatus):
+        stmt = update(Bill).where(Bill.id == bill_id).values(status=status).returning(Bill)
+        result = await session.execute(stmt)
+        await session.commit()
+        return result.scalar_one_or_none()