feat(users): govern profiles and access

Normalize fixed profile fields, profile actions, and the five-column capability matrix for comments, uploads, and downloads.

assets/admin/src/schema/sections/users/features.js

@@ -5,8 +5,6 @@ export const featuresSchema = {
   description: '配置用户中心和个人主页的功能模块。',
   defaults: {
     user_center_tabs: 'profile,level,posts,comments,favorites,vip,credits,revenue,auth',
-    user_cover_upload: true,
-    user_social_links: true,
     user_desc_std: '这家伙很懒…',
     user_city_s: true,
     user_city_type: 'province',
@@ -25,8 +23,6 @@ export const featuresSchema = {
       icon: 'fas fa-user-shield',
       fields: [
         { key: 'user_center_tabs', label: '用户中心 Tab', type: 'input', default: 'profile,level,comments,favorites,vip,credits,revenue,auth', help: '逗号分隔。level=我的等级；creator=创作中心；revenue=推广收益中心；auth=官方认证；等级、VIP、订单、创作中心、收益中心和认证会按功能开关自动注入' },
-        { key: 'user_cover_upload', label: '封面上传', type: 'switch', default: true },
-        { key: 'user_social_links', label: '社交链接', type: 'switch', default: true },
         { key: 'user_desc_std', label: '默认签名', type: 'input', default: '这家伙很懒…', help: '用户未设置个人简介时显示的默认文案' },
         { key: 'user_city_s', label: '显示城市（IP 归属地）', type: 'switch', default: true, help: '根据用户登录 IP 在用户主页与用户中心显示归属地；需同时在「扩展 → IP归属地」启用并勾选对应展示位置' },
         {