Replace MenuManagerCS2 with Panorama UI Kit for the admin menus and
css_vote. Layout names (menu, vote, banner, toast) are configurable
under MenuConfig and preloaded on startup; MenuType is removed and
ConfigVersion bumped to 26.
- Drop MenuManagerApi.dll and the old chat menu classes
- Reference PanoramaUiKit.Shared.dll, bump CounterStrikeSharp to 1.0.376
- Add .editorconfig and CODING_CONVENTIONS.md, apply them codebase-wide
- Remove the CS2-SimpleAdmin-docs site
- Rewrite README for the fork
