feat: 足球 LLM 预测服务初始提交

Profeto — 给 LLM 提供数据,让 LLM 预测足球比分。

核心模块:
- FastAPI 后端 + PostgreSQL (SQLAlchemy async)
- 多 Agent LLM 预测 (5 专家 + 终裁)
- 数据采集 (bzzoiro / understat / injuries)
- React 前端 (Vite + Tailwind)

包含:
- 数据源抽象 (DataSource 协议 + 注册表)
- Alembic 数据库迁移
- Prompt 模板 (单/多 Agent)
- 核心路径单元测试

src/db/base.py

@@ -0,0 +1,58 @@
+"""SQLAlchemy async engine + session。"""
+from __future__ import annotations
+
+from collections.abc import AsyncIterator
+
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+from sqlalchemy.orm import DeclarativeBase
+
+from src.core.config import settings
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+engine = create_async_engine(
+    settings.DATABASE_URL,
+    echo=False,
+    pool_pre_ping=True,
+    pool_size=10,
+    max_overflow=20,
+)
+
+AsyncSessionLocal = async_sessionmaker(
+    engine,
+    class_=AsyncSession,
+    expire_on_commit=False,
+    autocommit=False,
+    autoflush=False,
+)
+
+
+async def get_db() -> AsyncIterator[AsyncSession]:
+    """写路由用: 退出时自动 commit。"""
+    async with AsyncSessionLocal() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+        finally:
+            await session.close()
+
+
+async def get_db_read() -> AsyncIterator[AsyncSession]:
+    """读路由用: 不 commit(只读)。"""
+    async with AsyncSessionLocal() as session:
+        try:
+            yield session
+        finally:
+            await session.close()
+
+
+async def init_db() -> None:
+    """开发/测试用:建表。生产建议用 alembic。"""
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)