feat: support theme update and various improvements

- Add support for updating themes if a newer version is uploaded
- Hide config button for plugins without configuration items
- Auto refresh theme cache after panel update
- Fix issue where user used traffic cannot be set as a decimal
- Fix subscription issue for shadowrocket in v2board theme

app/Http/Controllers/V2/Admin/UserController.php

@@ -206,9 +206,10 @@ class UserController extends Controller
         if (!$user) {
             return $this->fail([400202, '用户不存在']);
         }
-        // 检查邮箱是否被使用
-        if (User::where('email', $params['email'])->first() && $user->email !== $params['email']) {
-            return $this->fail([400201, '邮箱已被使用']);
+        if (isset($params['email'])) {
+            if (User::where('email', $params['email'])->first() && $user->email !== $params['email']) {
+                return $this->fail([400201, '邮箱已被使用']);
+            }
         }
         // 处理密码
         if (isset($params['password'])) {
@@ -223,7 +224,6 @@ class UserController extends Controller
             if (!$plan) {
                 return $this->fail([400202, '订阅计划不存在']);
             }
-            // return json_encode($plan);
             $params['group_id'] = $plan->group_id;
         }
         // 处理邀请用户