refactor(typography): lazy getTypographySettingsStore + fix effect leak

Convert the eager typographySettingsStore singleton to getTypographySettingsStore()
(+ __resetTypographySettingsStore for tests) and update barrels and consumers
(TypographyMenu, FontSampler, SampleList, ComparisonView Line/SliderArea,
comparisonStore + its mock).

Fix a latent leak while here: the store ran $effect.root and discarded the
returned cleanup, so its storage-sync effects outlived every instance. Capture
the disposer and expose destroy(), which __reset now calls.

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

@@ -89,12 +89,14 @@ vi.mock('$features/AdjustTypography', () => ({
     })),
 }));
 
+const mockTypography = vi.hoisted(() => ({
+    weight: 400,
+    renderedSize: 48,
+    reset: vi.fn(),
+}));
+
 vi.mock('$features/AdjustTypography/model', () => ({
-    typographySettingsStore: {
-        weight: 400,
-        renderedSize: 48,
-        reset: vi.fn(),
-    },
+    getTypographySettingsStore: () => mockTypography,
 }));
 
 import * as proxyFonts from '$entities/Font/api/proxy/proxyFonts';