fix: 恢复租户应用订阅的自定义配置功能

定时任务提交(104487f)误删了 custom_configs 相关代码，现恢复：
- backend/app/models/tenant_app.py: 恢复 custom_configs 数据库字段
- backend/app/routers/tenant_apps.py: 恢复 CustomConfigItem、custom_configs 逻辑、get_token API

backend/app/models/tenant_app.py

@@ -23,6 +23,10 @@ class TenantApp(Base):
     # 功能权限
     allowed_tools = Column(Text)  # JSON 数组
     
+    # 自定义配置（JSON 数组）
+    # [{"key": "industry", "value": "medical_beauty", "remark": "医美行业"}, ...]
+    custom_configs = Column(Text)
+    
     status = Column(SmallInteger, default=1)
     created_at = Column(TIMESTAMP, default=datetime.now)
     updated_at = Column(TIMESTAMP, default=datetime.now, onupdate=datetime.now)

backend/app/routers/tenant_apps.py

@@ -17,6 +17,13 @@ router = APIRouter(prefix="/tenant-apps", tags=["应用配置"])
 
 # Schemas
 
+class CustomConfigItem(BaseModel):
+    """自定义配置项"""
+    key: str  # 配置键
+    value: str  # 配置值
+    remark: Optional[str] = None  # 备注说明
+
+
 class TenantAppCreate(BaseModel):
     tenant_id: str
     app_code: str = "tools"
@@ -25,6 +32,7 @@ class TenantAppCreate(BaseModel):
     access_token: Optional[str] = None  # 如果不传则自动生成
     allowed_origins: Optional[List[str]] = None
     allowed_tools: Optional[List[str]] = None
+    custom_configs: Optional[List[CustomConfigItem]] = None  # 自定义配置
 
 
 class TenantAppUpdate(BaseModel):
@@ -33,6 +41,7 @@ class TenantAppUpdate(BaseModel):
     access_token: Optional[str] = None
     allowed_origins: Optional[List[str]] = None
     allowed_tools: Optional[List[str]] = None
+    custom_configs: Optional[List[CustomConfigItem]] = None  # 自定义配置
     status: Optional[int] = None
 
 
@@ -111,6 +120,7 @@ async def create_tenant_app(
         access_token=access_token,
         allowed_origins=json.dumps(data.allowed_origins) if data.allowed_origins else None,
         allowed_tools=json.dumps(data.allowed_tools) if data.allowed_tools else None,
+        custom_configs=json.dumps([c.model_dump() for c in data.custom_configs], ensure_ascii=False) if data.custom_configs else None,
         status=1
     )
     db.add(app)
@@ -139,6 +149,14 @@ async def update_tenant_app(
         update_data['allowed_origins'] = json.dumps(update_data['allowed_origins']) if update_data['allowed_origins'] else None
     if 'allowed_tools' in update_data:
         update_data['allowed_tools'] = json.dumps(update_data['allowed_tools']) if update_data['allowed_tools'] else None
+    if 'custom_configs' in update_data:
+        if update_data['custom_configs']:
+            update_data['custom_configs'] = json.dumps(
+                [c.model_dump() if hasattr(c, 'model_dump') else c for c in update_data['custom_configs']], 
+                ensure_ascii=False
+            )
+        else:
+            update_data['custom_configs'] = None
     
     for key, value in update_data.items():
         setattr(app, key, value)
@@ -164,6 +182,27 @@ async def delete_tenant_app(
     return {"success": True}
 
 
+@router.get("/{app_id}/token")
+async def get_token(
+    app_id: int,
+    user: User = Depends(require_operator),
+    db: Session = Depends(get_db)
+):
+    """获取真实的 access_token（仅管理员可用）"""
+    app = db.query(TenantApp).filter(TenantApp.id == app_id).first()
+    if not app:
+        raise HTTPException(status_code=404, detail="应用配置不存在")
+    
+    # 获取应用的 base_url
+    app_info = db.query(App).filter(App.app_code == app.app_code).first()
+    base_url = app_info.base_url if app_info else ""
+    
+    return {
+        "access_token": app.access_token,
+        "base_url": base_url
+    }
+
+
 @router.post("/{app_id}/regenerate-token")
 async def regenerate_token(
     app_id: int,
@@ -207,6 +246,7 @@ def format_tenant_app(app: TenantApp, mask_secret: bool = True, db: Session = No
         "access_token": "******" if mask_secret and app.access_token else app.access_token,
         "allowed_origins": json.loads(app.allowed_origins) if app.allowed_origins else [],
         "allowed_tools": json.loads(app.allowed_tools) if app.allowed_tools else [],
+        "custom_configs": json.loads(app.custom_configs) if app.custom_configs else [],
         "status": app.status,
         "created_at": app.created_at,
         "updated_at": app.updated_at