chore: bump version to 2.4.3

- Fix critical Node.js DEP0190 security vulnerability in Windows npm package
- Add proper argument escaping to prevent command injection attacks
- Update all spawn() calls with platform-specific handling
- Add comprehensive changelog entry for security fix
- Maintain full cross-platform compatibility

Security fix resolves deprecation warning and secures Windows installations.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@kaitranntt/ccs",
-  "version": "2.4.2",
+  "version": "2.4.3",
   "description": "Claude Code Switch - Instant profile switching between Claude Sonnet 4.5 and GLM 4.6",
   "keywords": [
     "cli",