chore: add CI workflow + smoke test

Author: Indra

bunfig.toml

@@ -0,0 +1,3 @@
+[test]
+coverageSkipTestFiles = false
+coveragePathIgnorePatterns = []

src/index.ts

@@ -0,0 +1,2 @@
+// Re-export for coverage tracking (bun requires local source files for lcov generation)
+export * from "@coderbuzz/msgpack";

test/smoke.test.ts

@@ -1,5 +1,5 @@
 import { test, expect } from "bun:test";
-import { encode, decode, encodedSize } from "@coderbuzz/msgpack";
+import { encode, decode, encodedSize } from "../src/index";
 
 test("encode/decode string", () => {
   const buf = encode("hello");