feat: show deploy version on select-all (#2)

## Summary
- Inject git commit hash and build timestamp at build time via Vite's
`define` option
- Display deploy info in a hidden `<p>` element at the bottom of the
download page
- Text color matches background (`#fafafa`), only visible when user
selects all text (Ctrl+A / Cmd+A)

## Test plan
- [x] Build and deploy, then visit the page — deploy info should be
invisible
- [x] Press Ctrl+A / Cmd+A to select all text — deploy info (commit +
timestamp) should appear
- [x] Verify commit hash matches the deployed commit

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

Author: fengmk2

.github/workflows/ci.yml

@@ -5,6 +5,10 @@ on:
   pull_request:
     branches: [main]
 
+permissions:
+  contents: read
+  pull-requests: write
+
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -19,3 +23,30 @@ jobs:
       - run: vp check
       - run: vp build
       - run: vp test
+
+  staging-deploy:
+    needs: test
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: voidzero-dev/setup-vp@v1
+        with:
+          cache: true
+          registry-url: https://npm.pkg.github.com
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NODE_AUTH_TOKEN }}
+      - run: vpx void deploy
+        env:
+          VOID_TOKEN: ${{ secrets.VOID_TOKEN }}
+          VOID_PROJECT: vp-setup-staging
+      - name: Comment on PR
+        uses: actions/github-script@v7
+        with:
+          script: |
+            github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body: '✅ Staging deployment successful!\n\nPreview: https://vp-setup-staging.void.app/'
+            })

package.json

@@ -7,6 +7,7 @@
     "prepare": "vp config"
   },
   "devDependencies": {
+    "@types/node": "^25.5.2",
     "vite": "catalog:",
     "vite-plus": "catalog:",
     "void": "npm:@void-sdk/void@0.2.6"