Polish visual defects: color cards, spacing, date picker, file attachments, progress, input group, timeline, icon mappings ...

- demo: remove page background layer, add vertical spacing for demo rows
- palette: wrap color swatches in color cards with name/hex labels
- description list: style description-list-term distinctly
- file-upload: shrink attachment cards to 130px, increase gaps, center placeholder text
- forms: add .input-date styling with calendar icon and focus ring
- input-group: seamless action slot button without double borders
- progress: add vertical spacing between consecutive progress bars
- timeline: align marker connector line at left: 23px
- vue: make GnIconButton label optional, add Phosphor icon mappings
- tests: screenshot workflow passing, all 19 e2e tests green

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

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.

Sync tokens and components with Figma variables and frames ...

- Update primitive palette: add neutral-25, adjust warning-bg to #FEF3E5.
- Add full radius scale (xs/sm/md/lg/xl/2xl/full) from radius.tokens.json.
- Update semantic surfaces/borders from Mode 1 tokens.
- Realign buttons: primary dark, secondary mint, accent yellow, tertiary ghost.
- Realign badges, alerts, cards, inputs, checkbox, radio, switch, modal, toast.
- Update demo palette/utilities and style-guide docs.
- Add exported Figma frames and variables under 'figma design parts/' for reference.

Add Select, Textarea, and Card components ...

- Add _select.scss with native select wrapper and chevron.
- Extend _forms.scss with textarea styling.
- Add _cards.scss with default, filled, outlined, primary, secondary,
  elevated variants and sm/lg sizes.
- Add Vue adapters GnSelect, GnTextarea, GnCard matching gnexus-ui-kit API.
- Wire components into plugin and entry exports.
- Add demo partials for Select/Textarea and Cards.
- Update Vue example app and component coverage matrix.

Add Input, Badge, Alert components and foundation demos ...

- Add src/scss/components/_forms.scss with input, label, help text,
  and error/success/warning states.
- Add src/scss/components/_badges.scss and _alerts.scss with semantic
  variants and outline/size options.
- Add GnInput, GnBadge, GnAlert Vue adapters mirroring gnexus-ui-kit API.
- Update plugin and entry exports for new components.
- Add demo partials for Typography, Palette, Utilities, Inputs, Badges,
  and Alerts, and include them in demo/index.html.
- Extend Vue example app to render new components.