feat(fonts): implement Phase 4 - Update UI Components

- Replaced fontshareStore with unifiedFontStore in FontSearch.svelte
- Replaced fontshareStore with unifiedFontStore in SuggestedFonts.svelte
- Updated Font entity exports to include unifiedFontStore
- Updated model exports to include unified store exports
- Kept fontshareStore exports as deprecated for backward compatibility

Phase 4/7: Proxy API Integration for GlyphDiff

src/widgets/FontSearch/ui/FontSearch/FontSearch.svelte

@@ -4,7 +4,7 @@
     Combines search input with font list display
 -->
 <script lang="ts">
-import { fontshareStore } from '$entities/Font';
+import { unifiedFontStore } from '$entities/Font';
 import {
     FilterControls,
     Filters,
@@ -38,7 +38,7 @@ onMount(() => {
      * We "plug" this manager into the global store.
      * addBinding returns a function that removes this binding when the component unmounts.
      */
-    const unbind = fontshareStore.addBinding(() => mapManagerToParams(filterManager));
+    const unbind = unifiedFontStore.addBinding(() => mapManagerToParams(filterManager));
 
     return unbind;
 });