Add GitHub Pages deployment workflow

.github/workflows/deploy.yml

@@ -0,0 +1,74 @@
+name: Deploy Site to GitHub Pages
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    paths:
+      - "site/**"
+      - ".github/workflows/deploy.yml"
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  build:
+    name: Build Site
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: site
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+          cache-dependency-path: site/package-lock.json
+
+      - name: Setup Pages
+        id: pages
+        uses: actions/configure-pages@v5
+
+      - name: Install dependencies
+        run: npm ci --include=optional
+
+      - name: Work around npm optional dependency bug (Rollup native)
+        run: |
+          ROLLUP_NATIVE_PKG='@rollup/rollup-linux-x64-gnu'
+          if [ "$(uname -m)" = "aarch64" ]; then
+            ROLLUP_NATIVE_PKG='@rollup/rollup-linux-arm64-gnu'
+          fi
+          npm install --no-save "$ROLLUP_NATIVE_PKG"
+
+      - name: Build site
+        run: npm run build
+        env:
+          PUBLIC_SITE_BASE: ${{ steps.pages.outputs.base_path }}
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: site/dist
+
+  deploy:
+    name: Deploy to Pages
+    runs-on: ubuntu-latest
+    needs: build
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy
+        id: deployment
+        uses: actions/deploy-pages@v4

README.md

@@ -21,6 +21,13 @@ cd site
 npm run build
 ```
 
+For project pages (`https://<user>.github.io/<repo>/`), set `PUBLIC_SITE_BASE`:
+
+```bash
+cd site
+PUBLIC_SITE_BASE=/nue-lang.com/ npm run build
+```
+
 Theme can be selected at build time via `PUBLIC_THEME`:
 
 ```bash
@@ -33,6 +40,16 @@ PUBLIC_THEME=signal npm run build
 
 If `PUBLIC_THEME` is omitted, `signal` is used.
 
+## GitHub Pages Deploy
+
+The workflow `.github/workflows/deploy.yml` deploys `site/dist` to GitHub Pages on push to `main`.
+
+Setup once in repository settings:
+
+- `Settings > Pages > Source` to `GitHub Actions`
+
+`PUBLIC_SITE_BASE` is wired automatically by `actions/configure-pages` in CI.
+
 ## Home Playground Embed
 
 Home embeds the WASM playground as an Astro React island.

site/README.md

@@ -15,6 +15,12 @@ npm run dev
 npm run build
 ```
 
+For project pages (`https://<user>.github.io/<repo>/`), set `PUBLIC_SITE_BASE`:
+
+```bash
+PUBLIC_SITE_BASE=/nue-lang.com/ npm run build
+```
+
 ### Build with theme
 
 Set `PUBLIC_THEME` at build time.
@@ -28,7 +34,9 @@ PUBLIC_THEME=signal npm run build
 
 If omitted, `signal` is used.
 
-When deploying (for example to GitHub Pages), publish this `site/` directory only.
+When deploying with GitHub Pages via this repository, use `.github/workflows/deploy.yml`.
+The workflow publishes `site/dist` and sets `PUBLIC_SITE_BASE` automatically with
+`actions/configure-pages`.
 
 ## Home Playground Embed
 

site/astro.config.mjs

@@ -3,5 +3,7 @@ import mdx from "@astrojs/mdx";
 import react from "@astrojs/react";
 
 export default defineConfig({
+  output: "static",
+  base: process.env.PUBLIC_SITE_BASE || "/",
   integrations: [mdx(), react()]
 });