支持局域网 GPU OCR 服务，配置方式类似 Ollama。

backend/app/schemas/__init__.py

@@ -74,6 +74,7 @@ class SystemSettingsOut(BaseModel):
     openai_base_url: str | None = None
     openai_model: str | None = None
     openai_api_key_set: bool = False
+    ocr_service_url: str | None = None
     updated_at: datetime
 
     model_config = {"from_attributes": True}
@@ -87,6 +88,7 @@ class SystemSettingsUpdate(BaseModel):
     openai_base_url: str | None = None
     openai_model: str | None = None
     openai_api_key: str | None = None
+    ocr_service_url: str | None = None
 
 
 class AdminProfileUpdate(BaseModel):