ci: deploy Storybook to fixed production URL on main merge (#9373)

## Summary
- Add `deploy-production` job to Storybook CI workflow
- Triggers on push to `main` branch
- Deploys to fixed Cloudflare Pages URL:
`https://comfy-storybook.pages.dev`
- PR preview deployments remain unchanged

## Linked Issues
- Notion:
[COM-15826](https://www.notion.so/Deploy-Storybook-to-fixed-production-URL-on-main-branch-merge-3196d73d36508159a875d42694a619d1)

## Test Plan
- [ ] Merge to main and verify `deploy-production` job runs in GitHub
Actions
- [ ] Confirm `https://comfy-storybook.pages.dev` serves latest
Storybook
- [ ] Verify existing PR preview deployments still work
- [ ] Verify other jobs (comment, chromatic) are not affected by the new
trigger

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9373-ci-deploy-Storybook-to-fixed-production-URL-on-main-merge-3196d73d3650816795ead1a5b839a571)
by [Unito](https://www.unito.io)

.github/workflows/ci-tests-storybook.yaml

@@ -4,6 +4,8 @@ name: 'CI: Tests Storybook'
 on:
   workflow_dispatch: # Allow manual triggering
   pull_request:
+  push:
+    branches: [main]
 
 jobs:
   # Post starting comment for non-forked PRs
@@ -138,6 +140,29 @@ jobs:
             "${{ github.head_ref }}" \
             "completed"
 
+  # Deploy Storybook to production URL on main branch push
+  deploy-production:
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+
+      - name: Setup frontend
+        uses: ./.github/actions/setup-frontend
+
+      - name: Build Storybook
+        run: pnpm build-storybook
+
+      - name: Deploy to Cloudflare Pages (production)
+        env:
+          CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
+          CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
+        run: |
+          npx wrangler@^4.0.0 pages deploy storybook-static \
+            --project-name=comfy-storybook \
+            --branch=main
+
   # Update comment with Chromatic URLs for version-bump branches
   update-comment-with-chromatic:
     needs: [chromatic-deployment, deploy-and-comment]