explore: cap times and skill versions use #6b7280 so they meet WCAG AA

v0.4.1

feat(explore): differentiate cap and skill list rendering

reserve brand for display, add name for typing contexts

doctor: add bluesky session health check + status alias

add CONTRIBUTING.md describing vit-native contribution workflow

Add JavaScript/Bun port of plc_register.py

Add docs/ with GitHub Pages stub