Add GitHub Pages deployment workflow

Author: Your Name

.github/workflows/deploy-pages.yml

@@ -0,0 +1,53 @@
+name: Deploy to GitHub Pages
+
+on:
+  push:
+    branches: ["main"]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: SPA fallback for routes
+        run: cp dist/index.html dist/404.html
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist
+
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

vite.config.ts

@@ -5,6 +5,7 @@ import { componentTagger } from "lovable-tagger";
 
 // https://vitejs.dev/config/
 export default defineConfig(({ mode }) => ({
+  base: mode === "production" ? "/portfolio/" : "/",
   server: {
     host: "0.0.0.0",
     port: 8080,