Add Divider, Accordion, Stepper and FileAttachment components ...

- Implement CSS for divider, accordion, stepper and file-upload/attachment.
- Add browser Accordion helper and expose it on window.VMKUIKit.
- Add Vue adapters: GnAccordion, GnSteps, GnFileUpload, GnFileAttachment.
- Add demo partials and figma match pages for divider and attached-file.
- Fix Figma comparison flattening for transparent baselines (e.g. breadcrumbs, attached-file).
- Add vertical spacing to the demo index page to separate sections.

All Figma visual tests and the Vue adapter smoke build pass.

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.