feat: add structured pino logging and validated log-level config

test/logger.test.js

@@ -0,0 +1,12 @@
+"use strict";
+
+const test = require("node:test");
+const assert = require("node:assert/strict");
+const { createLogger } = require("../src/lib/logger");
+
+test("createLogger returns pino-compatible logger", () => {
+  const logger = createLogger({ level: "debug", name: "test" });
+  assert.equal(typeof logger.info, "function");
+  assert.equal(typeof logger.error, "function");
+  assert.equal(logger.level, "debug");
+});