Add dark mode, search, and fix broken links on website

[Copilot]

The website lacked dark mode support, search functionality, and had broken links on the improvements page due to slug mismatches.

Changes

Dark Mode

• Added ThemeToggle.js component with localStorage persistence
• Implemented CSS custom properties for theme switching (16 variables covering colors, backgrounds, borders)
• Theme transitions applied to all components with 0.3s ease timing

Search

• Created Search.js with client-side filtering using GraphQL search index
• Displays top 10 results in dropdown with title + excerpt
• Keyboard navigation: Enter submits to first result, Esc clears

Fixed Links

Updated improvements.js slugs from kebab-case to UPPERCASE_SNAKE_CASE to match actual document paths:

// Before: /phase2-implementation/
// After:  /PHASE2_IMPLEMENTATION/

All 6 improvement page links now resolve correctly (PHASE2_IMPLEMENTATION, RUST_MODERNIZATION_SUMMARY, TEST_UPDATES_SUMMARY, RUNTIME_ENFORCEMENT, VALIDATION_ENFORCEMENT, ENVIRONMENT_VARIABLE_MIGRATION).

Screenshots

Light Mode

Dark Mode

Search

Technical Details

• Header layout uses flexbox with justify-content: space-between for search + toggle positioning
• Theme state managed in component, synced to data-theme attribute on documentElement
• Search index built at build-time via static GraphQL query in Layout component
• Mobile responsive: header stacks vertically at 768px breakpoint

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• unpkg.com
  • Triggering command: /usr/local/bin/node node scripts/postinstall.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Please add dark mode to the website. There also needs to be search capabilities. Finally, many of the links are dead and return 404 errors. Please test links and ensure they actually link to something.

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