refactor: fix P0/P1/P2 security and performance issues

P0 fixes:
- CORS: replace wildcard methods/headers with configurable lists
- deps.py: remove unsafe global _warned_unset variable

P1 fixes:
- http_client: read default timeout from Settings
- bzzoiro: replace sync urllib with async httpx
- bzzoiro: normalize validation failures use warning level only
- db pool: read pool config from Settings (default 5+10)
- backtest: add asyncio.Semaphore(8) for concurrent execution
- predict/context_builder: add backtest parameter for cutoff buffer

P2 improvements:
- injuries: enforce int conversion for player_id/fixture_id
- injuries: use system temp dir for cache
- utils.py: extract shared actual_1x2/is_correct_1x2
- validation: downgrade 1x2 mismatch log to debug
- docker-compose: use env vars for all credentials
- .env.example: add POSTGRES_USER/PASSWORD/PORT, API_PORT

src/api/deps.py

@@ -19,24 +19,18 @@ from src.core.config import settings
 
 logger = logging.getLogger(__name__)
 
-_warned_unset = False
-
 
 async def require_admin_key(x_api_key: str | None = Header(None, alias="X-API-Key")) -> None:
     """保护「写入型 / 高成本」接口的依赖。
 
     用法: `@router.post("/ingest/bzzoiro", dependencies=[Depends(require_admin_key)])`
     """
-    global _warned_unset
-
     expected = settings.ADMIN_API_KEY
     if not expected:
-        if not _warned_unset:
-            logger.warning(
-                "ADMIN_API_KEY 未设置,采集/回测接口当前【无鉴权】。"
-                "生产环境请设置该环境变量。"
-            )
-            _warned_unset = True
+        logger.warning(
+            "ADMIN_API_KEY 未设置,采集/回测接口当前【无鉴权】。"
+            "生产环境请设置该环境变量。"
+        )
         return
 
     if not x_api_key or not secrets.compare_digest(x_api_key, expected):