Cloud Auth Backport (#6195)

## Summary

Backports Firebase authentication with cloud environments.

Changes only work when developing for cloud environment locally.

## Changes

- Router guards to force unauthenticated users to sign in.
- Configure auth headers for REST and Websocket connections.
- Code implemented in a way that enables build tree-shaking based on
distribution
- Updates to build process to build cloud distribution and simplify
development workflow

## Review Focus

1. Idomatic Vue/codebase patterns.
2. Build logic (please double check that I integrated correctly with:
https://github.com/Comfy-Org/ComfyUI_frontend/blob/rh-test/vite.config.mts)

## Screenshots (if applicable)




https://github.com/user-attachments/assets/ee4ea3f7-afa6-4da0-ba43-d62ed8ba4e18





┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6195-Feat-cloud-auth-backport-2946d73d365081f395f5f2a89fb7d800)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: GitHub Action <action@github.com>

src/composables/auth/useFirebaseAuthActions.ts

@@ -1,10 +1,12 @@
 import { FirebaseError } from 'firebase/app'
 import { AuthErrorCodes } from 'firebase/auth'
 import { ref } from 'vue'
+import { useRouter } from 'vue-router'
 
 import { useErrorHandling } from '@/composables/useErrorHandling'
 import type { ErrorRecoveryStrategy } from '@/composables/useErrorHandling'
 import { t } from '@/i18n'
+import { isCloud } from '@/platform/distribution/types'
 import { useToastStore } from '@/platform/updates/common/toastStore'
 import { useDialogService } from '@/services/dialogService'
 import { useFirebaseAuthStore } from '@/stores/firebaseAuthStore'
@@ -54,6 +56,16 @@ export const useFirebaseAuthActions = () => {
       detail: t('auth.signOut.successDetail'),
       life: 5000
     })
+
+    if (isCloud) {
+      try {
+        const router = useRouter()
+        await router.push({ name: 'cloud-login' })
+      } catch (error) {
+        // needed for local development until we bring in cloud login pages.
+        window.location.reload()
+      }
+    }
   }, reportError)
 
   const sendPasswordReset = wrapWithErrorHandlingAsync(