docs: add comprehensive Jinja macros documentation

New documentation:
- docs/frontend/shared/jinja-macros.md: Complete reference for all 94 macros
  - Alerts, Avatars, Badges, Buttons, Cards, Charts, Datepicker
  - Dropdowns, Forms, Headers, Modals, Pagination, Tables
  - Usage examples and parameter documentation
  - Complete page example showing all macros together

Updated documentation:
- docs/frontend/cdn-fallback-strategy.md:
  - Add Chart.js (v4.4.1) and Flatpickr (v4.6.13) sections
  - Document optional-libs.html loader macros
  - Update file structure and deployment checklist

- docs/frontend/shared/ui-components.md:
  - Add tip box recommending Jinja macros for new development
  - Update related documentation links

- mkdocs.yml:
  - Add Jinja Macros Library to navigation (top of Shared Components)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

mkdocs.yml

@@ -86,6 +86,7 @@ nav:
     - CDN Fallback Strategy: frontend/cdn-fallback-strategy.md
     - Tailwind CSS Build: frontend/tailwind-css.md
     - Shared Components:
+      - Jinja Macros Library: frontend/shared/jinja-macros.md
       - UI Components: frontend/shared/ui-components.md
       - UI Components Quick Reference: frontend/shared/ui-components-quick-reference.md
       - Pagination: frontend/shared/pagination.md