Исправления по результатам повторного визуального ревью: Vue form states, cluster utility, cards label, progress/loader demo ...

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

Use jpg avatar placeholder in demo partials ...

Switch all demo avatar references from /assets/avatar-placeholder.png
to /assets/avatar-placeholder.jpg as requested.

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

feat: add remaining reference Vue components, card variants, toolbar/repeater/activity-log/usage-meter styles and demo mounts ...

- Add GnHorizontalCard, GnUserCard, GnMetricCard, GnStatusCard, GnLoginCard,
  GnIdentity, GnActivityLog, GnToolbar, GnRouterTabs, GnRepeater, GnUsageMeter
- Extend GnTabs to support reference items API while keeping child mode
- Add card subcomponent styles: status, metric, horizontal, login, user
- Add toolbar, repeater, identity, activity-log, usage-meter styles
- Add typography token variables used by reference-compatible components
- Add Vue demo mounts for cards, data-patterns, progress, tabs, navigation-shell
- Fix GnAvatar online status class and navigation-shell footer slot
- Update screenshot config to cover skeleton and navigation-shell

Verified: npm run build, npm run test:e2e (19 passed), npm run screenshots,
npm run test:vue-adapter, figma-match (7 passed)

Add GnActionCard, GnActionList, GnCopyButton, GnRange and GnTagInput ...

- Mirror reference component APIs and register them in the Vue plugin and index.

- Add supporting styles for action-card, list-actions, range, tag-input and .btn-icon.

- Add Vue demo mounts to cards, lists and inputs partials.

- Capture Lists section in screenshot review.

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

Add Vue demo mounts for buttons, inputs, tables and capture inputs section ...

- Add GnButton, GnInput and GnTable Vue demo mounts.

- Switch tables partial to demo-section for screenshot capture.

- Add dismissible alert styles and close button.

- Include Inputs section in screenshot review list.

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

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.