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/core/config.py

@@ -32,6 +32,17 @@ class Settings(BaseSettings):
 
     # --- CORS ---
     CORS_ORIGINS: str = "http://localhost:5173,http://localhost:3000"
+    CORS_METHODS: str = "GET,POST,PUT,DELETE,OPTIONS"
+    CORS_HEADERS: str = "Authorization,Content-Type,X-API-Key,Accept"
+
+    # --- HTTP ---
+    HTTP_DEFAULT_TIMEOUT: int = 30
+
+    # --- database pool ---
+    DB_POOL_SIZE: int = 5
+    DB_MAX_OVERFLOW: int = 10
+    DB_POOL_TIMEOUT: int = 30
+    DB_POOL_RECYCLE: int = 1800
 
     # --- 管理接口鉴权 ---
     # 采集 / 回测等高成本或写入型接口需要此 Key(请求头 X-API-Key)。