refactor(Font): use pretext layout() directly in row size resolver

createFontRowSizeResolver was reaching into TextLayoutEngine, which
internally called pretext's heavy layoutWithLines and then walked
per-grapheme cursors to build chars arrays. The resolver discarded all
that work and used only totalHeight.

Replace with direct prepare + layout from @chenglou/pretext — pretext
docs explicitly recommend layout() (not layoutWithLines) for the resize
hot path: pure arithmetic on cached segment widths, no canvas calls, no
string allocations.

Test spies on TextLayoutEngine.prototype.layout migrated to vi.mock-ed
pretext layout (pretext's ESM exports are frozen — vi.spyOn fails with
"Cannot redefine property").

TextLayoutEngine marked @deprecated since it has no remaining
consumers; slated for removal after a release cycle.

src/entities/Font/lib/sizeResolver/createFontRowSizeResolver.ts

@@ -1,4 +1,7 @@
-import { TextLayoutEngine } from '$shared/lib';
+import {
+    layout,
+    prepare,
+} from '@chenglou/pretext';
 import { generateFontKey } from '../../model/store/fontLifecycleManager/utils/generateFontKey/generateFontKey';
 import type {
     FontLoadStatus,
@@ -79,14 +82,13 @@ export interface FontRowSizeResolverOptions {
  * no DOM snap occurs.
  *
  * **Caching:** A `Map` keyed by `fontCssString|text|contentWidth|lineHeightPx`
- * prevents redundant `TextLayoutEngine.layout()` calls. The cache is invalidated
+ * prevents redundant `pretext.layout()` calls. The cache is invalidated
  * naturally because a change in any input produces a different cache key.
  *
  * @param options - Configuration and getter functions (all injected for testability).
  * @returns A function `(rowIndex: number) => number` for use as `VirtualList.itemHeight`.
  */
 export function createFontRowSizeResolver(options: FontRowSizeResolverOptions): (rowIndex: number) => number {
-    const engine = new TextLayoutEngine();
     // Key: `${fontCssString}|${text}|${contentWidth}|${lineHeightPx}`
     const cache = new Map<string, number>();
 
@@ -126,7 +128,11 @@ export function createFontRowSizeResolver(options: FontRowSizeResolverOptions):
             return cached;
         }
 
-        const { totalHeight } = engine.layout(previewText, fontCssString, contentWidth, lineHeightPx);
+        // Pretext docs recommend `layout()` (not `layoutWithLines`) for the
+        // resize hot path — pure arithmetic on cached segment widths, no canvas
+        // calls, no string allocations.
+        const prepared = prepare(previewText, fontCssString);
+        const { height: totalHeight } = layout(prepared, contentWidth, lineHeightPx);
         const result = totalHeight + options.chromeHeight;
         cache.set(cacheKey, result);
         return result;