chore: add prepackage script to replace SVG badges with PNG

- Add prepackage/postpackage scripts to handle README SVG restriction
- Add mentioned-badge.png asset for marketplace compatibility

Initial commit: Claudix VSCode Extension

- Add complete DI architecture with service registry
- Implement Claude Agent SDK integration
- Add Vue 3 webview with Alien Signals reactive system
- Configure build system (esbuild + Vite)
- Add comprehensive documentation (README)
- Update branding to Claudix
- Change license to AGPL-3.0