全量修复:预测系统正确性、安全性与部署问题

P0 严重问题修复:
- 修复 form_slice/stats_slice 主客身份反转(历史比赛视角错误)
- 修复 understat.py httpx 未导入导致的 NameError
- 修复 LLM 解析失败时静默产生假成功预测(0-0 平局+置信度0.5)

预测路径修复:
- multi-agent 路径增加 backtest cutoff 透传,回测防泄漏生效
- H2H 切片汇总统计改为从当前主队视角计数
- 预测唯一约束增加 mode+run_type 维度,防止回测覆盖实盘预测

伤停管线修复:
- IntegrityError 后不再整批回滚丢数据(改用逐条 flush)
- return_date 正确解析并写入
- retrieved_at 比较统一用 date() 避免当天数据不可见
- 唯一索引改为 partial unique index(排除 NULL 重复)
- HTTP 缓存 TTL 从 7 天改为 6 小时

安全与连接管理:
- /api/v1/predict 增加内存滑动窗口限流(10次/分钟/IP)
- 预测路由改用短 session 模式,LLM 调用期间不持有 DB 连接

Docker 部署修复:
- 修复 .dockerignore 排除 *.md 导致 COPY README.md 失败
- 容器内 DATABASE_URL 使用 postgres 服务名(非 localhost)
- 启动时自动执行 alembic upgrade head
- 前端改用多阶段构建(Dockerfile.frontend)

新增测试(5个文件,24+用例):
- test_p0_home_away.py: 主客身份反转回归测试
- test_p0_parse_failure.py: LLM 解析失败回归测试
- test_multi_agent_cutoff.py: multi-agent cutoff 透传测试
- test_h2h_perspective.py: H2H 视角测试
- test_injuries_pipeline.py: 伤停管线 5 项修复测试
- test_predict_protection.py: 限流+短 session 测试
- test_prediction_unique_constraint.py: 唯一约束测试

迁移:
- 0012_injuries_partial_unique_and_return_date.py
- 0013_predictions_unique_constraint_mode_run_type.py

src/db/base.py

@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
 
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 from sqlalchemy.orm import DeclarativeBase
@@ -54,6 +55,38 @@ async def get_db_read() -> AsyncIterator[AsyncSession]:
             await session.close()
 
 
+@asynccontextmanager
+async def short_read():
+    """短生命周期 read session: 用于非路由上下文(如后台任务、手动调用)。
+
+    用法:
+        async with short_read() as session:
+            m = await session.get(Match, match_id)
+        # session 已关闭,连接已释放
+    """
+    async with AsyncSessionLocal() as session:
+        yield session
+
+
+@asynccontextmanager
+async def short_write():
+    """短生命周期 write session: 提交后立即释放。
+
+    用法:
+        async with short_write() as session:
+            session.add(pred)
+            await session.commit()
+        # session 已关闭,连接已释放
+    """
+    async with AsyncSessionLocal() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+
+
 async def init_db() -> None:
     """验证数据库连接(不建表)。
 

src/db/models.py

@@ -16,6 +16,7 @@ from sqlalchemy import (
     String,
     Text,
     UniqueConstraint,
+    and_,
     func,
 )
 from sqlalchemy.dialects.postgresql import JSONB
@@ -164,7 +165,19 @@ class Injury(Base):
     team: Mapped["Team | None"] = relationship()
 
     __table_args__ = (
-        Index("ix_injuries_player_fixture", "player_id", "fixture_id", "injury_type", unique=True),
+        # Fix 4: partial unique index — 只在 player_id 和 fixture_id 都非空时强制唯一
+        # PostgreSQL 中 NULL != NULL,普通唯一索引无法防止 NULL 重复
+        Index(
+            "ix_injuries_player_fixture",
+            "player_id",
+            "fixture_id",
+            "injury_type",
+            unique=True,
+            postgresql_where=and_(
+                player_id.is_not(None),
+                fixture_id.is_not(None),
+            ),
+        ),
         Index("ix_injuries_team_date", "team_id", "injury_date"),
     )
 
@@ -194,6 +207,8 @@ class Prediction(Base):
     agent_outputs: Mapped[dict | None] = mapped_column(JSONB)
     # 预测状态: success / failed / degraded
     status: Mapped[str] = mapped_column(String(20), nullable=False, default="success")
+    # Fix: run_type 区分实盘(live)与回测(backtest),避免回测覆盖实盘预测
+    run_type: Mapped[str] = mapped_column(String(10), nullable=False, default="live")
     # 时间语义:区分比赛时间、预测创建时间、数据截止时间
     match_kickoff_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     prediction_created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)
@@ -207,10 +222,11 @@ class Prediction(Base):
     match: Mapped[Match] = relationship(back_populates="predictions")
 
     __table_args__ = (
-        # P1-6: 数据库级唯一约束,防止同一 match+provider+model 产生重复预测
+        # Fix: 唯一约束增加 mode + run_type,允许 live 与 backtest 共存
+        # 防止回测覆盖未结算的实盘预测(后续 settle 会污染评估数据)
         UniqueConstraint(
-            "match_id", "provider", "model",
-            name="uq_predictions_match_provider_model",
+            "match_id", "provider", "model", "mode", "run_type",
+            name="uq_predictions_match_provider_model_mode_run_type",
         ),
         Index("ix_predictions_match", "match_id"),
         Index("ix_predictions_provider_model", "provider", "model"),
@@ -223,6 +239,7 @@ class Prediction(Base):
         CheckConstraint("pred_1x2 IN ('1', 'X', '2')", name="ck_pred_1x2_enum"),
         CheckConstraint("mode IN ('single', 'multi')", name="ck_mode_enum"),
         CheckConstraint("status IN ('success', 'failed', 'degraded')", name="ck_status_enum"),
+        CheckConstraint("run_type IN ('live', 'backtest')", name="ck_run_type_enum"),
     )