加速错题 OCR：上传压缩、识别缩放、启动预热与 MKL-DNN。

backend/app/core/config.py

@@ -19,9 +19,12 @@ class Settings(BaseSettings):
     FRONTEND_DIST: str = "../frontend/dist"
     ADMIN_DEFAULT_USERNAME: str = "admin"
     ADMIN_DEFAULT_PASSWORD: str = "admin123"
-    OCR_TIMEOUT_SECONDS: int = 300
+    OCR_TIMEOUT_SECONDS: int = 180
     AI_TIMEOUT_SECONDS: int = 600
     PROCESS_STALE_MINUTES: int = 20
+    OCR_MAX_SIDE: int = 1280
+    UPLOAD_MAX_SIDE: int = 2048
+    OCR_WARMUP: bool = True
 
     class Config:
         env_file = ".env"