Fix Vue demo: dark theme, label color, expanded component showcase ...

- demo/vue.html: replace broken CSS custom properties with real kit colors
  (body background #16161E, text #C0CAF5)
- demo/vue.html: update Vue CDN to 3.5.13
- demo/vue.html: expand demo to show 30+ components including
  Drawer, ConfirmDialog, Navigation, Progress, Timeline, Data Display,
  Identity, Chips, Toolbar, Overlays, EmptyState, Skeleton, Toasts
- _forms.scss: add color: $color-text-light to .label so labels are
  readable on dark backgrounds
- Add toast interaction demo buttons

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Improve Vue adapter usability, add router support, and fix animations ...

- Remove hover rotation from .btn-icon (SCSS)
- Fix iconNode to auto-prefix missing "ph-" and warn in dev
- Add CLAUDE.md as AI agent quick-reference for component usage
- Include src/vue/ and CLAUDE.md in published package files
- Add exports field wildcard for src/vue/* subpaths
- Reposition Vue adapter docs as primary contract (not thin wrapper)
- Add JSDoc @typedef to key Vue components (GnButton, GnInput, etc.)
- Add Vue demo page (demo/vue.html) linked from main navigation

Router support (optional, no hard dependency):
- Create useVueRouter composable with safe getCurrentInstance access
- Create GnRouterTabs component for route-driven tabs
- Add item.to support to GnNavList with auto-active and router.push
- Forward activeMatch through GnNavigationShell to GnNavList
- Register GnRouterTabs in plugin and index exports
- Update docs (README, CLAUDE, component-api, ai-usage-guide, component-map)

Fix missing close animations in Vue components:
- GnModal: a-hide transition before unmount (300ms)
- GnDrawer: a-hide transition before unmount (300ms)
- GnToastProvider: dismiss with a-hide animation, close for instant clear

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>