feat: get deals endpoint

services/deal.py

@@ -0,0 +1,15 @@
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from repositories.deal import DealRepository
+from schemas.deal import GetDealsResponse, DealSchema
+
+
+class DealService:
+    def __init__(self, session: AsyncSession):
+        self.repository = DealRepository(session)
+
+    async def get_deals(self, board_id: int) -> GetDealsResponse:
+        deals = await self.repository.get_all(board_id)
+        return GetDealsResponse(
+            deals=[DealSchema.model_validate(deal) for deal in deals]
+        )