ci: replace GitHub Pages action with Gitea Actions for Vercel deployment

Switch from GitHub Pages deployments to Vercel via Gitea Actions CLI.

.gitea/workflows/deploy.yml

@@ -0,0 +1,32 @@
+name: Deploy to Vercel
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+
+      - name: Install pnpm
+        run: npm install -g pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Build
+        run: pnpm build
+
+      - name: Deploy to Vercel
+        run: npx vercel deploy --prod --yes --token ${{ secrets.VERCEL_TOKEN }}
+        env:
+          VERCEL_PROJECT_ID: ${{ secrets.VERCEL_PROJECT_ID }}
+          VERCEL_ORG_ID: ${{ secrets.VERCEL_ORG_ID }}