Restyle tabs as a contained segment switcher ...

The tab list becomes a framed panel with inner padding, and
tabs are rounded chips inside it: subtle hover highlight,
filled primary active state, hairline separators removed.
Matches the demo theme switch style.

Add light border radius across components ...

- New tokens: $border-radius-sm (3px controls), $border-radius-md
  (6px panels), $border-radius-pill (switch track)
- Apply via hard_panel and per-component: buttons, inputs, tabs,
  range thumb, checkbox, switch, chips, avatars, dropdown/popover/
  tooltip panels, modal, toast, file upload, input group, code examples
- Drawer stays sharp (flush to screen edge)

v0.3.0 — GnUserCard, NavigationShell footer slot, Vue demo partials ...

Features:
- Add GnUserCard Vue component with compact and full variants
- Add GnNavigationShell #footer slot for custom footer content
- Add profile footer demo in navigation-shell section
- Split demo/vue.html into 27 partials under demo/partials/vue/
- Fix toast open animation (nextTick + requestAnimationFrame pattern)

Style:
- Add .user-card and .user-card-compact to _cards.scss
- Add .profile-identity to _navigation-shell.scss

Docs:
- Add demo synchronization rules to CLAUDE.md

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

Add tabs component and refresh modal/logo UI