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/ComparisonView/model/stores/comparisonStore.test.ts

@@ -71,7 +71,7 @@ vi.mock('$entities/Font', async importOriginal => {
     };
 });
 
-vi.mock('$features/SetupFont', () => ({
+vi.mock('$features/AdjustTypography', () => ({
     DEFAULT_TYPOGRAPHY_CONTROLS_DATA: [],
     createTypographyControlManager: vi.fn(() => ({
         weight: 400,
@@ -80,7 +80,7 @@ vi.mock('$features/SetupFont', () => ({
     })),
 }));
 
-vi.mock('$features/SetupFont/model', () => ({
+vi.mock('$features/AdjustTypography/model', () => ({
     typographySettingsStore: {
         weight: 400,
         renderedSize: 48,