fix: resolve dark mode code blocks and JavaScript errors after Tailwind migration

- Fix dark mode code block styling in chroma.css (background stays bright issue)
- Resolve JavaScript errors with window.hbb object initialization
- Fix Mermaid.js color parsing errors with proper CSS variable fallbacks
- Move inline JavaScript to external files for CSP compliance
- Create dedicated hb-search.js for search functionality
- Add proper error handling and validation for PagefindUI initialization
- Update .stylelintrc.yaml to disable no-descending-specificity rule
- Fix remaining lint issues: flex-flow shorthand and kebab-case IDs
- Ensure theme toggler functionality works correctly

Resolves regressions introduced during Tailwind 3→4 migration.
All functionality now works in both light and dark modes.

modules/blox-tailwind/assets/css/framework/base.css

@@ -3,7 +3,7 @@
   html {
     -webkit-font-smoothing: antialiased;
     -moz-osx-font-smoothing: grayscale;
-    text-rendering: optimizeLegibility;
+    text-rendering: optimizelegibility;
   }
   
   body {