Publish the app to GitHub Pages

.github/workflows/deploy-pages.yml

@@ -0,0 +1,47 @@
+name: Deploy to GitHub Pages
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+# Let the deployment write to Pages, and read the repo to build it.
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# One deployment at a time. Queue rather than cancel, so a push that lands
+# mid-deploy still ends up published.
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+      - run: npm ci
+      # The same gates CI runs. A broken build should not reach the live page.
+      - run: npm run typecheck
+      - run: npm test
+      - run: npm run build
+      - uses: actions/configure-pages@v5
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - id: deployment
+        uses: actions/deploy-pages@v4

README.md

@@ -7,6 +7,10 @@
 [![Tests](https://img.shields.io/badge/tests-51%20passing-brightgreen)](src/sim/__tests__)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
 
+### [Open it in your browser](https://algometrix.github.io/blackhole-sim/)
+
+No install, no account. It needs WebGL2, which every current desktop browser has.
+
 An interactive black hole visualizer that ray-traces **real Schwarzschild photon geodesics on the GPU**, per pixel, every frame. It renders the event horizon shadow, the photon ring, a Doppler-beamed accretion disc bent over and under the hole (the *Interstellar* look), and a gravitationally lensed starfield. You can launch photons and watch their true paths, drop a planet or star and watch it be tidally shredded, and place a second black hole to watch a gravitational-wave inspiral end in a merger, complete with a LIGO-style audio chirp.
 
 Everything runs in the browser. No backend, no textures, no libraries beyond Three.js: the stars, disc, physics, and sound are all procedural.

vite.config.ts

@@ -3,5 +3,8 @@ import glsl from 'vite-plugin-glsl';
 
 export default defineConfig({
   plugins: [glsl()],
+  // Relative asset URLs, so the same build works from a domain root and from
+  // the /blackhole-sim/ subpath GitHub Pages serves a project site at.
+  base: './',
   build: { target: 'es2022' },
 });