feat: 分离密码重置和修改密码功能

- 密码重置：用户忘记密码时通过邮箱/短信验证（需开启开关）
- 修改密码：已登录用户通过旧密码修改（固定功能，无需配置）
- 添加 EnablePasswordReset 开关控制密码重置功能
- PasswordResetMethod 只支持 email/sms 两种验证方式
- 添加短信配置管理功能
- 移除独立的应用邮箱设置页面

frontend/src/components/admin-sidebar/index.vue

@@ -1,5 +1,5 @@
 <script lang="ts" setup>
-import { Boxes, Code, CreditCard, DollarSign, FileLock, Gauge, GitBranch, HardDrive, Hash, Key, Mail, Megaphone, MessageSquare, Network, Plug, ScrollText, Settings, Shield, Users, Variable } from 'lucide-vue-next'
+import { Boxes, Code, CreditCard, DollarSign, FileLock, Gauge, GitBranch, HardDrive, Hash, Key, Mail, Megaphone, MessageSquare, Network, Plug, ScrollText, Settings, Shield, Smartphone, Users, Variable } from 'lucide-vue-next'
 import { onMounted, onUnmounted, reactive } from 'vue'
 
 import NavTeam from '@/components/app-sidebar/nav-team.vue'
@@ -193,6 +193,11 @@ const navMain = [
         url: '/admin/email-settings',
         icon: Mail,
       },
+      {
+        title: '短信配置',
+        url: '/admin/sms-settings',
+        icon: Smartphone,
+      },
       {
         title: '存储管理',
         url: '/admin/storage-configs',