固定生产商管理员角色

新建生产商时由服务端固定写入 admin，编辑时忽略并禁止修改角色。平台页面将 admin 只读显示为‘生产商管理员’，历史未知角色保持原值，不修改数据库或历史数据。补充后端回归测试、操作日志和项目文档。

frontend/platform_admin/src/api/resource-page-rules.ts

@@ -84,7 +84,6 @@ const pageRules: Record<string, ResourcePageRule> = {
       'address',
       'password',
       'display_name',
-      'role_code',
       'remark',
     ],
     editOptionalKeys: ['password'],

frontend/platform_admin/src/api/resources.ts

@@ -337,6 +337,18 @@ function fixedAdminRole(resource: string): ResourceField {
   });
 }
 
+/** 生产商当前只有管理员角色；历史未知编码继续按原值展示。 */
+function producerAdminRole(): ResourceField {
+  return f('role_code', {
+    label: '角色',
+    type: 'select',
+    required: true,
+    options: [{ label: '生产商管理员', value: 'admin' }],
+    defaultValue: 'admin',
+    readonlyOnCreate: true,
+  });
+}
+
 function define(
   name: string,
   title: string,
@@ -432,7 +444,7 @@ export const resources: ResourceUiDefinition[] = [
     }),
   ]),
 
-  define('producer_account', '生产商管理', 'writable', [f('producer_code', { required: true }), f('name', { required: true }), f('credit_code'), f('principal'), f('phone'), f('address', { emptyText: '未填写', placeholder: '请输入地址' }), f('username', { required: true }), f('password', { required: true }), f('display_name'), f('role_code'), f('remark')]),
+  define('producer_account', '生产商管理', 'writable', [f('producer_code', { required: true }), f('name', { required: true }), f('credit_code'), f('principal'), f('phone'), f('address', { emptyText: '未填写', placeholder: '请输入地址' }), f('username', { required: true }), f('password', { required: true }), f('display_name'), producerAdminRole(), f('remark')]),
   define('product_type', '智能气阀类型', 'editable', [f('code', { required: true }), f('name', { required: true })]),
   define('product_warehouse', '智能气阀库房', 'editable', [f('code', { required: true }), f('name', { required: true }), f('address'), f('manager'), f('phone')]),
   define('product_info', '智能气阀', 'editable', [f('code', { required: true }), f('name', { required: true }), relation('producer_account_identity', '/producer_account', true), relation('product_type_identity', '/product_type', true), f('params', { required: true }), relation('warehouse_identity', '/product_warehouse'), relation('gas_basic_identity', '/gas_basic'), relation('delivery_basic_identity', '/delivery_basic'), relation('user_account_identity', '/user_account'), f('produced_at', { required: true })], 'list', [