refactor: add main.ts decomposition guardrails and extract core helpers

src/cli/help.test.ts

@@ -0,0 +1,20 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { printHelp } from "./help";
+
+test("printHelp includes configured texthooker port", () => {
+  const original = console.log;
+  let output = "";
+  console.log = (value?: unknown) => {
+    output += String(value);
+  };
+
+  try {
+    printHelp(7777);
+  } finally {
+    console.log = original;
+  }
+
+  assert.match(output, /--help\s+Show this help/);
+  assert.match(output, /default: 7777/);
+});