Improve diffbudget release verification hygiene

.github/workflows/ci.yml

@@ -48,13 +48,12 @@ jobs:
             exit 1
           fi
 
-      - name: Run optional Node checks
+      - name: Run Node verification
         run: |
           set -euo pipefail
 
           if [ ! -f package.json ]; then
-            echo "No package.json found; skipping Node checks."
-            echo "TODO: add install, lint, test, typecheck, or build commands when this template becomes an app or package."
+            echo "No package.json found; skipping Node verification."
             exit 0
           fi
 
@@ -64,5 +63,7 @@ jobs:
             npm install
           fi
 
-          npm run release:check
-          bash scripts/validate.sh
+          npm run check
+          npm test
+          npm run build
+          npm run smoke

README.md

@@ -117,6 +117,19 @@ bash scripts/validate.sh
 
 Keep changes small, local-first, and fixture-backed. See [CONTRIBUTING.md](CONTRIBUTING.md) and [SECURITY.md](SECURITY.md).
 
+## Development
+
+Use Node.js 20 or newer. Run these checks before opening a PR:
+
+```sh
+npm run build
+npm run check
+npm test
+npm run smoke
+npm run package:smoke
+npm run release:check
+```
+
 ## License
 
 MIT

package.json

@@ -15,7 +15,9 @@
     "dist",
     "README.md",
     "LICENSE",
-    "SECURITY.md"
+    "SECURITY.md",
+    "CHANGELOG.md",
+    "CONTRIBUTING.md"
   ],
   "scripts": {
     "build": "tsc",