feat: add email verification check for cloud onboarding (#5636)

## Summary
- Added email verification flow for new users during onboarding
- Implemented invite code claiming with proper validation 
- Updated API endpoints from `/invite/` to `/invite_code/` for
consistency

## Changes

### Email Verification
- Added `CloudVerifyEmailView` component with email verification UI
- Added email verification check after login in `CloudLoginView`
- Added `isEmailVerified` property to Firebase auth store
- Users must verify email before claiming invite codes

### Invite Code Flow
- Enhanced `CloudClaimInviteView` with full claim invite functionality
- Updated `InviteCheckView` to route users based on email verification
status
- Modified API to return both `claimed` and `expired` status for invite
codes
- Added proper error handling and Sentry logging for invite operations

### API Updates
- Changed endpoint paths from `/invite/` to `/invite_code/` 
- Updated `getInviteCodeStatus()` to return `{ claimed: boolean;
expired: boolean }`
- Updated `claimInvite()` to return `{ success: boolean; message: string
}`

### UI/UX Improvements
- Added Korean translations for all new strings
- Improved button styling and layout in survey and waitlist views
- Added proper loading states and error handling

## Test Plan
- [ ] Test new user signup flow with email verification
- [ ] Test invite code validation (expired/claimed/valid codes)
- [ ] Test email verification redirect flow
- [ ] Test invite claiming after email verification
- [ ] Verify Korean translations display correctly

🤖 Generated with [Claude Code](https://claude.ai/code)

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/stores/firebaseAuthStore.ts

@@ -9,6 +9,7 @@ import {
   browserLocalPersistence,
   createUserWithEmailAndPassword,
   onAuthStateChanged,
+  sendEmailVerification,
   sendPasswordResetEmail,
   setPersistence,
   signInWithEmailAndPassword,
@@ -75,6 +76,9 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
   const isAuthenticated = computed(() => !!currentUser.value)
   const userEmail = computed(() => currentUser.value?.email)
   const userId = computed(() => currentUser.value?.uid)
+  const isEmailVerified = computed(
+    () => currentUser.value?.emailVerified ?? false
+  )
 
   // Get auth from VueFire and listen for auth state changes
   // From useFirebaseAuth docs:
@@ -289,6 +293,14 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
     await updatePassword(currentUser.value, newPassword)
   }
 
+  /** Send email verification to current user */
+  const verifyEmail = async (): Promise<void> => {
+    if (!currentUser.value) {
+      throw new FirebaseAuthStoreError(t('toastMessages.userNotAuthenticated'))
+    }
+    await sendEmailVerification(currentUser.value)
+  }
+
   const addCredits = async (
     requestBodyContent: CreditPurchasePayload
   ): Promise<CreditPurchaseResponse> => {
@@ -364,6 +376,7 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
     // State
     loading,
     currentUser,
+    isEmailVerified,
     isInitialized,
     balance,
     lastBalanceUpdateTime,
@@ -387,6 +400,7 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
     accessBillingPortal,
     sendPasswordReset,
     updatePassword: _updatePassword,
-    getAuthHeader
+    getAuthHeader,
+    verifyEmail
   }
 })