refactor(features): rename SetupFont to AdjustTypography + reorganize

Structural:
- Merge factory + singleton from lib/settingsManager and model/state into
  one model/store/typographySettingsStore/ slice
- Drop now-empty lib/ and model/state/ directories

Semantic:
- Rename feature SetupFont -> AdjustTypography (the feature owns
  continuous typography adjustment, not one-time font setup)
- Drop "Manager" from TypographySettingsManager -> TypographySettingsStore
  (class + factory); singleton typographySettingsStore unchanged

All consumers (Character, Line, SampleList, SliderArea, FontSampler,
comparisonStore) updated. Public barrel signature changed: now exports
createTypographySettingsStore and type TypographySettingsStore.

src/widgets/SampleList/ui/SampleList/SampleList.svelte

@@ -11,11 +11,11 @@ import {
     createFontRowSizeResolver,
     fontStore,
 } from '$entities/Font';
-import { FontSampler } from '$features/DisplayFont';
 import {
     TypographyMenu,
     typographySettingsStore,
-} from '$features/SetupFont';
+} from '$features/AdjustTypography';
+import { FontSampler } from '$features/DisplayFont';
 import { throttle } from '$shared/lib/utils';
 import { Skeleton } from '$shared/ui';
 import { layoutManager } from '../../model';