Fix ES module imports by adding .js extensions

- Added .js extensions to all import statements in source files
- Fixes ERR_MODULE_NOT_FOUND error when using package with Node.js
- Version bumped to 0.2.2

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@xtr-dev/rondevu-client",
-  "version": "0.2.1",
+  "version": "0.2.2",
   "description": "TypeScript client for Rondevu peer signaling and discovery server",
   "type": "module",
   "main": "dist/index.js",