移动端拍照上传、奥数区、学段约束解题与 AI 模型配置。

- 手机/平板响应式布局，支持拍照与相册上传

- 学生详情新增奥数区，按初/高中学段生成解法并禁止超纲

- 系统设置可配置 Ollama 或 OpenAI 兼容 API

- 更新 frontend/dist 与使用说明

backend/app/schemas/__init__.py

@@ -18,6 +18,16 @@ class WrongQuestionStatusEnum(str, Enum):
     failed = "failed"
 
 
+class WrongQuestionCategoryEnum(str, Enum):
+    regular = "regular"
+    olympiad = "olympiad"
+
+
+class AIProviderEnum(str, Enum):
+    ollama = "ollama"
+    openai = "openai"
+
+
 class SchoolLevelEnum(str, Enum):
     junior_high = "junior_high"
     senior_high = "senior_high"
@@ -58,6 +68,12 @@ class PublicSettingsOut(BaseModel):
 
 class SystemSettingsOut(BaseModel):
     registration_enabled: bool
+    ai_provider: AIProviderEnum
+    ollama_base_url: str | None = None
+    ollama_model: str | None = None
+    openai_base_url: str | None = None
+    openai_model: str | None = None
+    openai_api_key_set: bool = False
     updated_at: datetime
 
     model_config = {"from_attributes": True}
@@ -65,6 +81,12 @@ class SystemSettingsOut(BaseModel):
 
 class SystemSettingsUpdate(BaseModel):
     registration_enabled: bool | None = None
+    ai_provider: AIProviderEnum | None = None
+    ollama_base_url: str | None = None
+    ollama_model: str | None = None
+    openai_base_url: str | None = None
+    openai_model: str | None = None
+    openai_api_key: str | None = None
 
 
 class AdminProfileUpdate(BaseModel):
@@ -207,6 +229,7 @@ class WrongQuestionOut(BaseModel):
     student_id: UUID
     subject_id: int
     subject_name: str | None = None
+    category: WrongQuestionCategoryEnum
     image_path: str
     ocr_raw_text: str | None
     question_text: str | None