Complete core ES module migration with build system and tests

- Enhanced build system to generate ESM, UMD, and minified formats
- Fixed test extraction script to properly parse OxJS inline tests
- Added comprehensive test infrastructure with Vitest
- Successfully extracted 22 test files from inline documentation
- Verified builds work in browser and Node.js environments
- Maintained full backward compatibility with Ox.load() pattern
- Updated .gitignore to exclude build artifacts (dev/, min/, dist/, test/extracted/)

Generated with AI assistance

vitest.config.js

@@ -5,7 +5,7 @@ export default defineConfig({
   test: {
     globals: true,
     environment: 'node', // Use node for now to avoid jsdom issues
-    setupFiles: './test/setup.js'
+    setupFiles: './test/test-setup.js'
   },
   resolve: {
     alias: {