refactor: Sprint 3 - 引入 UnitOfWork + Repository 架构

新增:
- src/db/unit_of_work.py: UnitOfWork 事务封装
- src/db/repositories.py: Match/Team/League/Prediction Repository

重构:
- 删除 src/data/match_lookup.py(由 Repository 替代)
- 数据源(bzzoiro/understat/injuries)不再自行 commit
- API 路由(ingest)改用 UnitOfWork
- LLM 服务(predict/orchestrator/eval/backtest)改用 UnitOfWork

事务边界统一由调用方控制,数据层不再自行决定 commit。

src/api/routes/ingest.py

@@ -6,7 +6,7 @@ from fastapi import APIRouter, HTTPException
 from src.api.schemas import IngestBzzoiroRequest, IngestResponse, IngestUnderstatRequest, IngestInjuriesRequest, IngestSimpleResponse
 from src.data.sources import get_source
 from src.data.injuries import ingest_injuries
-from src.db.base import AsyncSessionLocal
+from src.db.unit_of_work import get_uow
 
 router = APIRouter(prefix="/api/v1", tags=["ingest"])
 
@@ -15,42 +15,41 @@ router = APIRouter(prefix="/api/v1", tags=["ingest"])
 async def ingest_bzzoiro_route(req: IngestBzzoiroRequest):
     """触发 bzzoiro 采集。"""
     source = get_source("bzzoiro")
-    async with AsyncSessionLocal() as db:
-        try:
+    try:
+        async with get_uow() as uow:
             result = await source.ingest(
-                db,
+                uow.session,
                 leagues=req.leagues,
                 date_from=req.date_from,
                 date_to=req.date_to,
                 status=req.status,
             )
-            await db.commit()
-            return IngestResponse(**result)
-        except Exception as e:
-            await db.rollback()
-            raise HTTPException(500, str(e))
+            await uow.commit()
+        return IngestResponse(**result)
+    except Exception as e:
+        raise HTTPException(500, str(e))
 
 
 @router.post("/ingest/understat", response_model=IngestSimpleResponse)
 async def ingest_understat_route(req: IngestUnderstatRequest):
     """触发 understat xG 回填。"""
     source = get_source("understat")
-    async with AsyncSessionLocal() as db:
-        try:
-            result = await source.ingest(db, league=req.league, season=req.season)
-            return IngestSimpleResponse(**result)
-        except Exception as e:
-            await db.rollback()
-            raise HTTPException(500, str(e))
+    try:
+        async with get_uow() as uow:
+            result = await source.ingest(uow.session, league=req.league, season=req.season)
+            await uow.commit()
+        return IngestSimpleResponse(**result)
+    except Exception as e:
+        raise HTTPException(500, str(e))
 
 
 @router.post("/ingest/injuries", response_model=IngestSimpleResponse)
 async def ingest_injuries_route(req: IngestInjuriesRequest):
     """触发伤停采集。"""
-    async with AsyncSessionLocal() as db:
-        try:
-            result = await ingest_injuries(db, date=req.date)
-            return IngestSimpleResponse(**result)
-        except Exception as e:
-            await db.rollback()
-            raise HTTPException(500, str(e))
+    try:
+        async with get_uow() as uow:
+            result = await ingest_injuries(uow.session, date=req.date)
+            await uow.commit()
+        return IngestSimpleResponse(**result)
+    except Exception as e:
+        raise HTTPException(500, str(e))