feat: Sprint 1 - 数据正确性整改

P2-01: 移除 lifespan create_all,改为仅验证连接
       新增 /health/ready 就绪检查
P0-04: LLM 输出严格 Pydantic 校验
       - Agent 输出越界/非法 → parse_error
       - 预测输出自动修正 1X2 与比分一致性
P0-01: injuries cutoff 修复
       - get_injuries_for_match 增加 as_of 参数
       - injuries_slice 使用 as_of 过滤 retrieved_at
       - 防止回测时未来采集数据泄漏
P1-12: 批量入库优化
       - 预加载 teams 到内存 dict
       - 预加载 existing matches 到内存 set
       - 消灭 N+1 查询

src/llm/context_builder.py

@@ -219,12 +219,16 @@ async def home_away_slice(header: MatchHeader, *, limit: int = 10, before=None)
 
 
 async def injuries_slice(header: MatchHeader, *, before=None) -> str:
-    """D - 阵容完整性切片: 伤停与停赛名单,评估战力缺失程度。"""
+    """D - 阵容完整性切片: 伤停与停赛名单,评估战力缺失程度。
+
+    before=cutoff: 只使用 cutoff 之前已采集的伤停数据,防回测泄漏。
+    """
     from src.data.injuries import get_injuries_for_match
 
+    cutoff = before or header.match_dt
     async with AsyncSessionLocal() as db:
-        home_injuries = await get_injuries_for_match(db, header.home_team_id, before or header.match_dt)
-        away_injuries = await get_injuries_for_match(db, header.away_team_id, before or header.match_dt)
+        home_injuries = await get_injuries_for_match(db, header.home_team_id, cutoff, as_of=cutoff)
+        away_injuries = await get_injuries_for_match(db, header.away_team_id, cutoff, as_of=cutoff)
 
     lines = ["── 阵容完整性 ──"]
     has_data = False