ci: add shared manual Vercel deployment

.gitea/scoped_workflows/vercel-manual.yml

@@ -0,0 +1,29 @@
+name: Deploy to Vercel
+
+on:
+  workflow_dispatch:
+    inputs:
+      environment:
+        description: Deployment environment
+        type: choice
+        options:
+          - preview
+          - production
+        default: preview
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    env:
+      VERCEL_ORG_ID: ${{ secrets.VERCEL_ORG_ID }}
+      VERCEL_PROJECT_ID: ${{ secrets.VERCEL_PROJECT_ID }}
+      DEPLOY_ENV: ${{ inputs.environment }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Deploy
+        run: |
+          npm install --global vercel@59.17.0
+          if [ "$DEPLOY_ENV" = production ]; then PROD=--prod; else PROD=; fi
+          vercel pull --yes --environment="$DEPLOY_ENV" --token="${{ secrets.VERCEL_TOKEN }}"
+          vercel build $PROD --token="${{ secrets.VERCEL_TOKEN }}"
+          vercel deploy --prebuilt --archive=tgz $PROD --token="${{ secrets.VERCEL_TOKEN }}"