chore: bump version to 4.3.0

Full feature parity release - all 42 SDKs now implement:
- Complete API coverage (58+ functions matching un.h spec)
- HTTP 428 sudo OTP challenge handling
- Comprehensive unit, integration, and functional tests

clients/javascript/async/package.json

@@ -1,6 +1,6 @@
 {
   "name": "un-async",
-  "version": "4.2.50",
+  "version": "4.3.0",
   "description": "Unsandbox async JavaScript SDK - Execute code in 50+ languages",
   "main": "src/un_async.js",
   "type": "module",

clients/javascript/sync/package.json

@@ -1,6 +1,6 @@
 {
   "name": "un-sync",
-  "version": "4.2.50",
+  "version": "4.3.0",
   "description": "unsandbox.com JavaScript SDK (Isomorphic - Node.js + Browser)",
   "type": "module",
   "main": "src/un.js",