Remove the GitHub Actions deploy job

.github/workflows/build.yml

@@ -0,0 +1,54 @@
+name: Build
+
+# Railway deploys main itself, through its GitHub integration. This workflow checks that
+# every pull request and every push to main builds.
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+# A newer push supersedes an in-flight check on the same branch.
+concurrency:
+  group: build-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  # Railway builds from the Dockerfile too, but a red check here points at the actual
+  # error rather than at a remote build log.
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: 22
+          cache: npm
+
+      - run: npm ci
+
+      # The route table and search index are generated and gitignored, so they must exist
+      # before tsc runs — a fresh checkout has neither.
+      - name: Generate routes and search index
+        run: npm run gen
+
+      - name: Typecheck
+        run: npx tsc --noEmit
+
+      - name: Heading anchors match the previously published site
+        run: node scripts/test-slug.mjs
+
+      - name: Build
+        run: npm run build
+
+      - name: Every page prerendered
+        run: |
+          count=$(find dist -name index.html | wc -l)
+          echo "prerendered $count pages"
+          test "$count" -ge 35

README.md

@@ -61,9 +61,9 @@ Images go in `public/images/` and are referenced from `.mdx` as `/images/…`.
 - **Netlify / Cloudflare Pages** — the generated `dist/_redirects` is already correct
 - **S3 + CloudFront** — index document `index.html`, error document `404.html`, plus a rule
   mapping `/path` to `/path/index.html`
-- **Railway** — pushes to `main` deploy automatically via
-  `.github/workflows/deploy.yml`; `railway up` from this directory does it by hand.
-  `railway.json` selects the Dockerfile.
+- **Railway** — pushes to `main` deploy automatically through Railway's GitHub
+  integration; `railway up` from this directory does it by hand. `railway.json` selects the
+  Dockerfile.
 
 Assets under `/assets/` and `/fonts/` are content-hashed or never edited in place and are served
 `immutable`; HTML revalidates.
@@ -121,17 +121,12 @@ smears every stem.
 
 ## CI
 
-`.github/workflows/deploy.yml`:
+`.github/workflows/build.yml` runs on pull requests to `main` and on pushes to `main`:
+`npm run gen`, `tsc --noEmit`, the anchor test, `npm run build`, and an assertion that at
+least 35 pages prerendered.
 
-- **pull requests to `main`** — build check only: `npm run gen`, `tsc --noEmit`,
-  the anchor test, `npm run build`, and an assertion that all 35 pages prerendered.
-- **pushes to `main`** — the same check, then `railway up`, then it waits until the live
-  `index.html` byte-matches this commit's build and smoke-tests four routes plus a 404.
-  Deploys never run from a pull request.
-
-Requires one repository secret, **`RAILWAY_TOKEN`** — a Railway *project* token for the
-`production` environment (Railway dashboard → project → Settings → Tokens). Without it the
-deploy job fails immediately with a message saying so, rather than half-deploying.
+Deploying is not part of CI. Railway's GitHub integration builds the Dockerfile and deploys
+every push to `main`.
 
 ## Verifying the rendering