fix: 修复邮箱快捷登录前端回调兜底

frontend/src/components/auth/EmailOAuthButtons.vue

@@ -34,6 +34,7 @@ import GoogleMark from './GoogleMark.vue'
 import { resolveAffiliateReferralCode, storeOAuthAffiliateCode } from '@/utils/oauthAffiliate'
 
 type EmailOAuthProvider = 'github' | 'google'
+const EMAIL_OAUTH_PENDING_PROVIDER_KEY = 'email_oauth_pending_provider'
 
 const props = withDefaults(defineProps<{
   disabled?: boolean
@@ -73,6 +74,7 @@ function startLogin(provider: EmailOAuthProvider): void {
   const redirectTo = (route.query.redirect as string) || '/dashboard'
   const affiliateCode = resolveAffiliateReferralCode(props.affCode, route.query.aff, route.query.aff_code)
   storeOAuthAffiliateCode(affiliateCode)
+  window.sessionStorage.setItem(EMAIL_OAUTH_PENDING_PROVIDER_KEY, provider)
   const apiBase = (import.meta.env.VITE_API_BASE_URL as string | undefined) || '/api/v1'
   const normalized = apiBase.replace(/\/$/, '')
   const params = new URLSearchParams({ redirect: redirectTo })

frontend/src/components/auth/__tests__/EmailOAuthButtons.spec.ts

@@ -57,6 +57,7 @@ describe('EmailOAuthButtons', () => {
       '/api/v1/auth/oauth/github/start?redirect=%2Fbilling%3Fplan%3Dpro&aff_code=AFF123'
     )
     expect(window.sessionStorage.getItem('oauth_aff_code')).toBe('AFF123')
+    expect(window.sessionStorage.getItem('email_oauth_pending_provider')).toBe('github')
   })
 
   it('uses a full-width descriptive button when only GitHub is enabled', () => {