fix: deploy website previews via GitHub Actions instead of Vercel auto-deploy (#11289)

## Summary

Vercel's auto-deploy triggers on every PR because files outside
workspace packages (e.g. `browser_tests/`, `src/`) are treated as global
changes by the monorepo skip logic.

## Changes

- **What**: Replace Vercel's GitHub integration with a GitHub Action
(`ci-vercel-website-preview.yaml`) that uses `paths:` filtering to only
deploy when `apps/website/`, `packages/design-system/`, or
`packages/tailwind-utils/` change. Add `vercel.json` with
`github.enabled: false` to disable Vercel's automatic GitHub
integration.

## Setup required after merge

Three GitHub repo secrets are needed. All secrets are scoped per-project
using the `VERCEL_WEBSITE_*` prefix. Future Vercel projects would follow
the same convention (e.g. `VERCEL_DOCS_*`).

### Step 1: Create a Vercel API Token

1. Go to [vercel.com/account/tokens](https://vercel.com/account/tokens)
2. Click **Create Token**
3. Fill in the form:
   - **Token Name**: `github-actions-website`
- **Scope**: Select the **Comfy-Org** team (not "Full Account" — scope
it to the team that owns the project)
- **Expiration**: Choose **No Expiration** (or set a long expiration
like 1 year — if it expires the workflow will silently fail)
4. Click **Create**
5. **Copy the token immediately** — it is only shown once

### Step 2: Get Vercel Org ID and Project ID

1. Go to
[vercel.com/comfyui/website-frontend/settings](https://vercel.com/comfyui/website-frontend/settings)
2. Scroll down to the **Project ID** field — copy this value
3. Go to
[vercel.com/teams/comfyui/settings](https://vercel.com/teams/comfyui/settings)
(Team Settings → General)
4. Find the **Vercel ID** field (also called Team ID / Org ID) — copy
this value

### Step 3: Add secrets to GitHub

1. Go to
[github.com/Comfy-Org/ComfyUI_frontend/settings/secrets/actions](https://github.com/Comfy-Org/ComfyUI_frontend/settings/secrets/actions)
2. Click **New repository secret** and add each of the three secrets:

| Secret name | Value |
|---|---|
| `VERCEL_WEBSITE_TOKEN` | The token from Step 1 |
| `VERCEL_WEBSITE_ORG_ID` | The team/org ID from Step 2 |
| `VERCEL_WEBSITE_PROJECT_ID` | The project ID from Step 2 |

> **Note:** The `vercel.json` added by this PR (`github.enabled: false`)
automatically disables Vercel's built-in auto-deploy — no dashboard
changes needed.

## Review Focus

- Verify the `paths:` filter covers all dependencies of `apps/website`
- Confirm the PR comment logic is sound (creates once, updates on
subsequent pushes)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: DrJKL <DrJKL0424@gmail.com>
Co-authored-by: Amp <amp@ampcode.com>

.github/workflows/ci-vercel-website-preview.yaml

@@ -0,0 +1,90 @@
+---
+name: 'CI: Vercel Website Preview'
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+    paths:
+      - 'apps/website/**'
+      - 'packages/design-system/**'
+      - 'packages/tailwind-utils/**'
+  push:
+    branches: [main]
+    paths:
+      - 'apps/website/**'
+      - 'packages/design-system/**'
+      - 'packages/tailwind-utils/**'
+
+env:
+  VERCEL_ORG_ID: ${{ secrets.VERCEL_WEBSITE_ORG_ID }}
+  VERCEL_PROJECT_ID: ${{ secrets.VERCEL_WEBSITE_PROJECT_ID }}
+
+jobs:
+  deploy-preview:
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v4.4.0
+
+      - name: Install Vercel CLI
+        run: npm install --global vercel@latest
+
+      - name: Pull Vercel environment information
+        run: vercel pull --yes --environment=preview --token=${{ secrets.VERCEL_WEBSITE_TOKEN }}
+
+      - name: Build project artifacts
+        run: vercel build --token=${{ secrets.VERCEL_WEBSITE_TOKEN }}
+
+      - name: Deploy project artifacts to Vercel
+        id: deploy
+        run: |
+          URL=$(vercel deploy --prebuilt --token=${{ secrets.VERCEL_WEBSITE_TOKEN }})
+          echo "url=$URL" >> "$GITHUB_OUTPUT"
+
+      - name: Add deployment URL to summary
+        run: echo "**Preview:** ${{ steps.deploy.outputs.url }}" >> "$GITHUB_STEP_SUMMARY"
+
+      - name: Save PR metadata
+        run: |
+          mkdir -p temp/vercel-preview
+          echo "${{ steps.deploy.outputs.url }}" > temp/vercel-preview/url.txt
+
+      - name: Upload preview metadata
+        uses: actions/upload-artifact@v6
+        with:
+          name: vercel-preview
+          path: temp/vercel-preview
+
+  deploy-production:
+    if: github.event_name == 'push'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v4.4.0
+
+      - name: Install Vercel CLI
+        run: npm install --global vercel@latest
+
+      - name: Pull Vercel environment information
+        run: vercel pull --yes --environment=production --token=${{ secrets.VERCEL_WEBSITE_TOKEN }}
+
+      - name: Build project artifacts
+        run: vercel build --prod --token=${{ secrets.VERCEL_WEBSITE_TOKEN }}
+
+      - name: Deploy project artifacts to Vercel
+        id: deploy
+        run: |
+          URL=$(vercel deploy --prebuilt --prod --token=${{ secrets.VERCEL_WEBSITE_TOKEN }})
+          echo "url=$URL" >> "$GITHUB_OUTPUT"
+
+      - name: Add deployment URL to summary
+        run: echo "**Production:** ${{ steps.deploy.outputs.url }}" >> "$GITHUB_STEP_SUMMARY"