Fix "Validation failed" when editing env variables with null labels (#3026)

* Initial plan

* Fix env variable edit validation error when labels is null

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

back/api/env.ts

@@ -49,7 +49,7 @@ export default (app: Router) => {
             .required()
             .pattern(/^[a-zA-Z_][0-9a-zA-Z_]*$/),
           remarks: Joi.string().optional().allow(''),
-          labels: Joi.array().items(Joi.string().trim()).optional(),
+          labels: Joi.array().items(Joi.string().trim()).optional().allow(null),
         }),
       ),
     }),
@@ -76,7 +76,7 @@ export default (app: Router) => {
         name: Joi.string().required(),
         remarks: Joi.string().optional().allow('').allow(null),
         id: Joi.number().required(),
-        labels: Joi.array().items(Joi.string().trim()).optional(),
+        labels: Joi.array().items(Joi.string().trim()).optional().allow(null),
       }),
     }),
     async (req: Request, res: Response, next: NextFunction) => {

src/pages/env/modal.tsx

@@ -35,7 +35,7 @@ const EnvModal = ({
         payload = [{ value, name, remarks, labels: labels || [] }];
       }
     } else {
-      payload = { ...values, id: env.id };
+      payload = { ...values, labels: values.labels || [], id: env.id };
     }
     try {
       const { code, data } = await request[method](