[fix] Improve cloud onboarding UX with email verification polling and signup flow (#6030)

## Summary
Improve cloud onboarding flow by adding email verification polling and
fixing signup auto-logout issue.

## Changes
- **What**: 
- Add polling mechanism to automatically check email verification status
every 5 seconds on the verify email page
- Fix auto-logout issue after signup by redirecting to root instead of
login page
- Remove automatic logout on login page mount to preserve user session
after signup
- **Breaking**: None
- **Dependencies**: None

## Review Focus
- Email verification polling implementation uses Firebase Auth's
`reload()` method to refresh user state
- Polling stops after 5 minutes to prevent indefinite resource usage
- Proper cleanup of intervals/timeouts in `onUnmounted` hook to prevent
memory leaks
- Signup flow now maintains user session instead of forcing re-login

## User Experience Improvements
1. **Before**: Users had to manually refresh the page after clicking
email verification link
**After**: Page automatically detects verification and proceeds to next
step

2. **Before**: After signup, users were redirected to login page and
automatically logged out, requiring them to sign in again
**After**: Users stay logged in after signup and are redirected to root,
maintaining their session

## Testing
- Tested email verification polling with both verified and unverified
states
- Verified that invite codes are preserved throughout the flow
- Confirmed no memory leaks from polling intervals
- Tested signup flow with email/password authentication

## Related Issues
- Resolves user complaints about having to sign in twice during signup
flow
- Addresses email verification page not auto-advancing after
verification

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6030-fix-Improve-cloud-onboarding-UX-with-email-verification-polling-and-signup-flow-28a6d73d365081be8020caee6337c3e7)
by [Unito](https://www.unito.io)

src/platform/onboarding/cloud/CloudLoginView.vue

@@ -104,7 +104,7 @@
 import Button from 'primevue/button'
 import Divider from 'primevue/divider'
 import Message from 'primevue/message'
-import { computed, onMounted, ref } from 'vue'
+import { computed, ref } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { useRoute, useRouter } from 'vue-router'
 
@@ -179,8 +179,4 @@ const signInWithEmail = async (values: SignInData) => {
     await onSuccess()
   }
 }
-
-onMounted(async () => {
-  await authActions.logout()
-})
 </script>

src/platform/onboarding/cloud/CloudSignupView.vue

@@ -117,7 +117,8 @@ const navigateToLogin = () => {
 }
 
 const onSuccess = async () => {
-  await router.push({ name: 'cloud-login', query: route.query })
+  // The invite code will be handled after the user is logged in
+  await router.push({ path: '/', query: route.query })
 }
 
 // Custom error handler for inline display

src/platform/onboarding/cloud/CloudVerifyEmailView.vue

@@ -35,19 +35,54 @@
 </template>
 
 <script setup lang="ts">
-import { onMounted } from 'vue'
+import { onMounted, onUnmounted, ref } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { useRoute, useRouter } from 'vue-router'
+import { useFirebaseAuth } from 'vuefire'
 
 import { useToastStore } from '@/platform/updates/common/toastStore'
 import { useFirebaseAuthStore } from '@/stores/firebaseAuthStore'
 
 const authStore = useFirebaseAuthStore()
+const auth = useFirebaseAuth()!
 
 const router = useRouter()
 const route = useRoute()
 const { t } = useI18n()
 
+let intervalId: number | null = null
+let timeoutId: number | null = null
+const redirectInProgress = ref(false)
+
+function clearPolling(): void {
+  if (intervalId !== null) {
+    clearInterval(intervalId)
+    intervalId = null
+  }
+  if (timeoutId !== null) {
+    clearTimeout(timeoutId)
+    timeoutId = null
+  }
+}
+
+async function redirectToNextStep(): Promise<void> {
+  if (redirectInProgress.value) return
+
+  redirectInProgress.value = true
+  clearPolling()
+
+  const inviteCode = route.query.inviteCode as string | undefined
+
+  if (inviteCode) {
+    await router.push({
+      name: 'cloud-invite-check',
+      query: { inviteCode }
+    })
+  } else {
+    await router.push({ name: 'cloud-user-check' })
+  }
+}
+
 const goBack = async () => {
   const inviteCode = route.query.inviteCode as string | undefined
   const authStore = useFirebaseAuthStore()
@@ -86,23 +121,35 @@ async function onSend() {
 }
 
 onMounted(async () => {
-  // When this screen loads via invite flow,
-  // ensure the invite code stays in the URL for the next step.
-  const inviteCode = route.query.inviteCode as string | undefined
-
   // If the user is already verified (email link already clicked),
   // continue to the next step automatically.
   if (authStore.isEmailVerified) {
-    if (inviteCode) {
-      await router.push({
-        name: 'cloud-invite-check',
-        query: inviteCode ? { inviteCode } : {}
-      })
-    } else {
-      await router.push({ name: 'cloud-user-check' })
-    }
-  } else {
-    await onSend()
+    return redirectToNextStep()
   }
+
+  // Send initial verification email
+  await onSend()
+
+  // Start polling to check email verification status
+  intervalId = window.setInterval(async () => {
+    if (auth.currentUser && !redirectInProgress.value) {
+      await auth.currentUser.reload()
+      if (auth.currentUser?.emailVerified) {
+        void redirectToNextStep()
+      }
+    }
+  }, 5000) // Check every 5 seconds
+
+  // Stop polling after 5 minutes
+  timeoutId = window.setTimeout(
+    () => {
+      clearPolling()
+    },
+    5 * 60 * 1000
+  )
+})
+
+onUnmounted(() => {
+  clearPolling()
 })
 </script>