feat(admin): 修改密码页 + 首次登录强制改密；自绘标题栏与管理面板 Electron 窗口

web/src/admin/api/client.ts

@@ -154,6 +154,14 @@ export const adminApi = {
       },
     ),
 
+  changePassword: (currentPassword: string, newPassword: string): Promise<{ relogin: boolean }> =>
+    call(
+      () => client.auth.changePassword(currentPassword, newPassword),
+      () => {
+        throw new ApiError('INTERNAL', '示例数据模式下无法修改密码', 0)
+      },
+    ),
+
   health: (): Promise<HealthInfo> =>
     call(
       () => client.health(),

web/src/admin/api/mock.ts

@@ -715,6 +715,7 @@ class MockDb {
       username,
       displayName: username === '' ? '示例用户' : username,
       role: 'admin',
+      mustChangePassword: false,
       lastLoginAt: null,
     }
   }