enhance release v2 experience

scripts/check-feature-contracts.mts

@@ -0,0 +1,14 @@
+import { resolve } from "node:path";
+
+import { checkFeatureContracts } from "./feature-platform/contracts.mts";
+
+const root = resolve(import.meta.dirname, "..");
+const problems = checkFeatureContracts(root);
+
+if (problems.length > 0) {
+  console.error("Feature contract check failed:");
+  for (const problem of problems) console.error(`\n- ${problem.message}\n  Repair: ${problem.repair}`);
+  process.exitCode = 1;
+} else {
+  console.log("Feature contracts are consistent.");
+}