feat(ocr,form-creator): Add comprehensive font support and TypeScript type definitions

- Add @pdf-lib/fontkit dependency for enhanced font rendering capabilities
- Create font-mappings.ts configuration with language-to-font-family mappings for 100+ languages
- Implement font-loader.ts utility for dynamic font loading from CDN sources
- Add TypeScript type definitions for form-creator, OCR, and general application types
- Create types/index.ts as centralized type exports
- Remove hidden-on-touch CSS class and update shortcuts button styling for better accessibility
- Update OCR text layer rendering to support multilingual font families
- Enhance form-creator with improved font handling for international text
- Update txt-to-pdf with font support for diverse character sets
- Migrate fileHandler to support new font loading workflow
- Update main.ts and ui.ts to integrate new type system and font utilities
- Update form-creator.html page with enhanced font configuration UI

index.html

@@ -280,7 +280,7 @@
             <kbd id="shortcut"
               class="bg-gray-800 px-2.5 py-1.5 rounded-md text-xs font-semibold text-gray-300 border border-gray-700 shadow-sm"></kbd>
             <button id="open-shortcuts-btn"
-              class="p-1 hover:bg-gray-600 rounded-md text-gray-400 hover:text-white transition-colors hidden-on-touch"
+              class="p-1 hover:bg-gray-600 rounded-md text-gray-400 hover:text-white transition-colors"
               title="Keyboard Shortcuts">
               <i data-lucide="settings" class="w-4 h-4"></i>
             </button>