Features:
- New GnTagInput Vue component with inline chip display
- Enter / paste (with separator split) to add tags
- Backspace in empty field removes last tag
- Unique check and maxItems limit
- Removable chips with x button

Style:
- Add _tag-input.scss with .tag-input, .tag-input-wrap, .tag-input-field
- Chips reuse existing .chip-secondary styling

Demo:
- Add interactive tag input example to Forms section (vanilla + Vue)
- Add code example blocks for HTML and Vue usage

Docs:
- Add GnTagInput to CLAUDE.md component catalog

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