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/widgets/TypographySettings/ui/TypographyMenu.svelte

@@ -24,7 +24,7 @@ const [send, receive] = crossfade({
 
 {#if displayedFontsStore.hasAnyFonts}
     <div
-        class="w-auto fixed bottom-5 left-1/2 translate-x-[-50%] max-w-max z-10"
+        class="w-auto fixed bottom-5 inset-x-0 max-screen z-10 flex justify-center"
         in:receive={{ key: 'panel' }}
         out:send={{ key: 'panel' }}
     >