Final polish, functional audit, and new Vue components ...

- Fix interactive overlay pointer-events for modal/drawer
- Add accordion panel transition so animation completes
- Fix toast inline handler syntax escaping
- Install real Phosphor Icons fonts and CSS
- Add auto-init for browser helpers and GNexusUIKit alias
- Add functional Playwright tests for all interactive components
- Add new Vue components: GnIconButton, GnInputGroup, GnDescriptionList, GnEmptyState, GnPageHeader
- Update kit.scss with new component styles
- All 17 e2e tests, Vue adapter smoke, and production build passing

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

Scaffold vmk-ui-kit build system, docs, and compatibility contract ...

- Add Gulp 5 + esbuild + Sass build pipeline mirroring gnexus-ui-kit
- Add package.json with compatible exports (main, module, vue, css, assets)
- Add Playwright config and smoke test
- Add Vue example project for adapter smoke build
- Add placeholder SCSS tokens, JS entry, and Vue plugin
- Add docs skeleton (getting-started, vue, style-guide, release, coverage)
- Add PROJECT_NOTES.md with agreed decisions and open questions
- Update CLAUDE.md with reference architecture and compatibility requirements

Build, Vue example build, and Playwright smoke test all pass.