feat(fonts): implement Phase 6 - Cleanup and Removal

- Deleted src/entities/Font/model/store/googleFontsStore.svelte.ts
- Deleted src/entities/Font/model/store/fontshareStore.svelte.ts
- Deleted src/entities/Font/model/services/fetchGoogleFonts.svelte.ts
- Deleted src/entities/Font/model/services/fetchFontshareFonts.svelte.ts
- Deleted src/entities/Font/model/services/index.ts
- Updated Font entity exports to remove deprecated stores
- Updated model index exports to remove deprecated services
- Updated store index to only export unified store

Phase 6/7: Proxy API Integration for GlyphDiff

src/entities/Font/model/index.ts

@@ -34,8 +34,6 @@ export type {
     UnifiedFontVariant,
 } from './types';
 
-export { fetchFontshareFontsQuery } from './services';
-
 export {
     appliedFontsManager,
     createUnifiedFontStore,
@@ -43,10 +41,3 @@ export {
     type UnifiedFontStore,
     unifiedFontStore,
 } from './store';
-
-// DEPRECATED: Fontshare store (kept for backward compatibility)
-export {
-    createFontshareStore,
-    type FontshareStore,
-    fontshareStore,
-} from './store/fontshareStore.svelte';