feat(registration): add email domain whitelist policy

frontend/src/i18n/locales/en.ts

@@ -312,6 +312,9 @@ export default {
     passwordMinLength: 'Password must be at least 6 characters',
     loginFailed: 'Login failed. Please check your credentials and try again.',
     registrationFailed: 'Registration failed. Please try again.',
+    emailSuffixNotAllowed: 'This email domain is not allowed for registration.',
+    emailSuffixNotAllowedWithAllowed:
+      'This email domain is not allowed. Allowed domains: {suffixes}',
     loginSuccess: 'Login successful! Welcome back.',
     accountCreatedSuccess: 'Account created successfully! Welcome to {siteName}.',
     reloginRequired: 'Session expired. Please log in again.',
@@ -3528,6 +3531,11 @@ export default {
         enableRegistrationHint: 'Allow new users to register',
         emailVerification: 'Email Verification',
         emailVerificationHint: 'Require email verification for new registrations',
+        emailSuffixWhitelist: 'Email Domain Whitelist',
+        emailSuffixWhitelistHint:
+          'Only email addresses from the specified domains can register (for example, @qq.com, @gmail.com)',
+        emailSuffixWhitelistPlaceholder: 'example.com',
+        emailSuffixWhitelistInputHint: 'Leave empty for no restriction',
         promoCode: 'Promo Code',
         promoCodeHint: 'Allow users to use promo codes during registration',
         invitationCode: 'Invitation Code Registration',

frontend/src/i18n/locales/zh.ts

@@ -312,6 +312,8 @@ export default {
     passwordMinLength: '密码至少需要 6 个字符',
     loginFailed: '登录失败，请检查您的凭据后重试。',
     registrationFailed: '注册失败，请重试。',
+    emailSuffixNotAllowed: '该邮箱域名不在允许注册范围内。',
+    emailSuffixNotAllowedWithAllowed: '该邮箱域名不被允许。可用域名：{suffixes}',
     loginSuccess: '登录成功！欢迎回来。',
     accountCreatedSuccess: '账户创建成功！欢迎使用 {siteName}。',
     reloginRequired: '会话已过期，请重新登录。',
@@ -3698,6 +3700,11 @@ export default {
         enableRegistrationHint: '允许新用户注册',
         emailVerification: '邮箱验证',
         emailVerificationHint: '新用户注册时需要验证邮箱',
+        emailSuffixWhitelist: '邮箱域名白名单',
+        emailSuffixWhitelistHint:
+          '仅允许使用指定域名的邮箱注册账号（例如 @qq.com, @gmail.com）',
+        emailSuffixWhitelistPlaceholder: 'example.com',
+        emailSuffixWhitelistInputHint: '留空则不限制',
         promoCode: '优惠码',
         promoCodeHint: '允许用户在注册时使用优惠码',
         invitationCode: '邀请码注册',