feat(FN-5189): complete Step 5 — guard against nohup regressions

Fusion-Task-Id: FN-5189
Fusion-Task-Lineage: 4caa3f0a-af81-4c60-88e8-de229ed72e08

scripts/__tests__/check-no-nohup.test.mjs

@@ -0,0 +1,28 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const checkerModule = await import(["..", "/check-no-no", "hup", ".mjs"].join(""));
+const { formatFailureMessage, scanFileContent } = checkerModule;
+const bannedToken = ["no", "hup"].join("");
+
+test("scanFileContent reports banned token matches", () => {
+  const source = `pnpm ${bannedToken} dev`;
+  const matches = scanFileContent(source, "scripts/example.mjs");
+  assert.equal(matches.length, 1);
+  assert.equal(matches[0].lineNumber, 1);
+  assert.match(matches[0].line, new RegExp(bannedToken));
+});
+
+test("scanFileContent ignores allowlisted lines", () => {
+  const source = `// process-supervisor-allowlist: ${bannedToken} mention is explanatory only`;
+  const matches = scanFileContent(source, "scripts/example.mjs");
+  assert.equal(matches.length, 0);
+});
+
+test("formatFailureMessage points callers at superviseSpawn", () => {
+  const message = formatFailureMessage([
+    { filePath: "scripts/example.mjs", lineNumber: 3, line: `pnpm ${bannedToken} dev` },
+  ]);
+  assert.match(message, /superviseSpawn/);
+  assert.match(message, /scripts\/example\.mjs:3/);
+});