WIP-CHECKPOINT[auth-refactor]: 固化工程师崩溃前部分成果 + 同树其他未提交WIP（仅源码，不含密钥/二进制）-- 待重激活工程师续作

backend/app/schemas/agent.py

@@ -41,9 +41,17 @@ class AgentLogin(BaseModel):
 
     user_id: str = Field(..., min_length=1, max_length=64, description="企微用户ID")
     name: str = Field(..., min_length=1, max_length=128, description="坐席姓名")
-    otp_code: Optional[str] = Field(None, min_length=6, max_length=6, description="OTP动态码（6位数字）")
+    otp_code: Optional[str] = Field(None, description="OTP动态码（6位数字）")
     password: Optional[str] = Field(None, description="本地密码（可选）")
 
+    @field_validator('otp_code')
+    @classmethod
+    def validate_otp_code(cls, v):
+        """OTP验证码验证：有值时必须是6位数字"""
+        if v is not None and (len(v) != 6 or not v.isdigit()):
+            raise ValueError('OTP验证码必须是6位数字')
+        return v
+
 
 # --------------------------------------------------------------------------
 # 坐席状态更新 Schema