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>

Prepare package release flow

Add Vue package smoke test

Document Vue adapter usage and package checks

Add remaining Vue CSS wrappers

Harden Vue adapter smoke path

Add Vue adapter foundation

Add navigation shell component

Modernize Sass build pipeline

Scaffold GNexus UI kit