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/features/AdjustTypography/ui/TypographyMenu/TypographyMenu.stories.svelte

@@ -0,0 +1,45 @@
+<script module>
+import Providers from '$shared/lib/storybook/Providers.svelte';
+import { defineMeta } from '@storybook/addon-svelte-csf';
+import TypographyMenu from './TypographyMenu.svelte';
+
+const { Story } = defineMeta({
+    title: 'Features/TypographyMenu',
+    component: TypographyMenu,
+    tags: ['autodocs'],
+    parameters: {
+        docs: {
+            description: {
+                component:
+                    'Floating typography controls. Mobile/tablet: settings button that opens a popover. Desktop: inline bar with combo controls.',
+            },
+            story: { inline: false },
+        },
+        layout: 'centered',
+        storyStage: { maxWidth: 'max-w-xl' },
+    },
+    argTypes: {
+        hidden: { control: 'boolean' },
+    },
+});
+</script>
+
+<Story name="Desktop">
+    {#snippet template()}
+        <Providers>
+            <div class="relative h-20 flex items-end justify-center p-4">
+                <TypographyMenu />
+            </div>
+        </Providers>
+    {/snippet}
+</Story>
+
+<Story name="Hidden">
+    {#snippet template()}
+        <Providers>
+            <div class="relative h-20 flex items-end justify-center p-4">
+                <TypographyMenu hidden={true} />
+            </div>
+        </Providers>
+    {/snippet}
+</Story>