feat(fonts): implement Phase 1 - Create Proxy API Client

- Created src/entities/Font/api/proxy/proxyFonts.ts
- Implemented fetchProxyFonts function with full pagination support
- Implemented fetchProxyFontById convenience function
- Added TypeScript interfaces: ProxyFontsParams, ProxyFontsResponse
- Added comprehensive JSDoc documentation
- Updated src/entities/Font/api/index.ts to export proxy API

Phase 1/7: Proxy API Integration for GlyphDiff

src/entities/Font/api/index.ts

@@ -4,6 +4,17 @@
  * Exports API clients and normalization utilities
  */
 
+// Proxy API (PRIMARY - NEW)
+export {
+    fetchProxyFontById,
+    fetchProxyFonts,
+} from './proxy/proxyFonts';
+export type {
+    ProxyFontsParams,
+    ProxyFontsResponse,
+} from './proxy/proxyFonts';
+
+// Google Fonts API (DEPRECATED - kept for backward compatibility)
 export {
     fetchGoogleFontFamily,
     fetchGoogleFonts,
@@ -14,6 +25,7 @@ export type {
     GoogleFontsResponse,
 } from './google/googleFonts';
 
+// Fontshare API (DEPRECATED - kept for backward compatibility)
 export {
     fetchAllFontshareFonts,
     fetchFontshareFontBySlug,