refactor(font): absorb FetchFontsByIds store into Font entity

FetchFontsByIds was data-access for the Font aggregate wearing a feature
costume: a single FontsByIdsStore (BaseQueryStore over Font's proxy API),
no UI, consumed only by comparisonStore. Move it beside fontCatalogStore
in the Font entity, collapse its deep $entities/Font imports to relative
paths, expose via the Font public API, and delete the feature slice.

src/entities/Font/model/store/fontsByIdsStore/fontsByIdsStore.svelte.ts

@@ -1,14 +1,14 @@
+import { fontKeys } from '$shared/api/queryKeys';
+import { BaseQueryStore } from '$shared/lib';
 import {
     fetchFontsByIds,
     seedFontCache,
-} from '$entities/Font/api/proxy/proxyFonts';
+} from '../../../api/proxy/proxyFonts';
 import {
     FontNetworkError,
     FontResponseError,
-} from '$entities/Font/lib/errors/errors';
-import type { UnifiedFont } from '$entities/Font/model/types';
-import { fontKeys } from '$shared/api/queryKeys';
-import { BaseQueryStore } from '$shared/lib';
+} from '../../../lib/errors/errors';
+import type { UnifiedFont } from '../../types';
 
 /**
  * Internal fetcher that seeds the cache and handles error wrapping.

src/entities/Font/model/store/fontsByIdsStore/fontsByIdsStore.test.ts

@@ -1,8 +1,3 @@
-import * as api from '$entities/Font/api/proxy/proxyFonts';
-import {
-    FontNetworkError,
-    FontResponseError,
-} from '$entities/Font/lib/errors/errors';
 import { queryClient } from '$shared/api/queryClient';
 import { fontKeys } from '$shared/api/queryKeys';
 import {
@@ -12,6 +7,11 @@ import {
     it,
     vi,
 } from 'vitest';
+import * as api from '../../../api/proxy/proxyFonts';
+import {
+    FontNetworkError,
+    FontResponseError,
+} from '../../../lib/errors/errors';
 import { FontsByIdsStore } from './fontsByIdsStore.svelte';
 
 describe('FontsByIdsStore', () => {

src/entities/Font/model/store/index.ts

@@ -7,3 +7,6 @@ export {
     FontCatalogStore,
     fontCatalogStore,
 } from './fontCatalogStore/fontCatalogStore.svelte';
+
+// Batch fetch by IDs (detail-cache seeding)
+export { FontsByIdsStore } from './fontsByIdsStore/fontsByIdsStore.svelte';

src/features/FetchFontsByIds/index.ts

@@ -1 +0,0 @@
-export { FontsByIdsStore } from './model';

src/features/FetchFontsByIds/model/index.ts

@@ -1 +0,0 @@
-export { FontsByIdsStore } from './store/fontsByIdsStore/fontsByIdsStore.svelte';

src/widgets/ComparisonView/model/stores/comparisonStore.svelte.ts

@@ -15,13 +15,13 @@
 
 import {
     type FontLoadRequestConfig,
+    FontsByIdsStore,
     type UnifiedFont,
     fontCatalogStore,
     fontLifecycleManager,
     getFontUrl,
 } from '$entities/Font';
 import { typographySettingsStore } from '$features/AdjustTypography/model';
-import { FontsByIdsStore } from '$features/FetchFontsByIds';
 import { createPersistentStore } from '$shared/lib';
 import { untrack } from 'svelte';
 import { getPretextFontString } from '../../lib';