first commit

.github/scripts/enforce-package-manager.js

@@ -0,0 +1,25 @@
+const userAgent = process.env.npm_config_user_agent || '';
+
+if (/\bpnpm\//.test(userAgent)) {
+    process.exit(0);
+}
+
+const detectedPackageManager = userAgent.split(' ')[0] || 'unknown';
+
+console.error(`
+Ghost now uses pnpm for dependency installation.
+
+Detected package manager: ${detectedPackageManager}
+
+Use one of these instead:
+  corepack enable pnpm
+  pnpm install
+
+Common command replacements:
+  yarn setup   -> pnpm run setup
+  yarn dev     -> pnpm dev
+  yarn test    -> pnpm test
+  yarn lint    -> pnpm lint
+`);
+
+process.exit(1);