test(layoutStore): silence expected warn in invalid-JSON case

The "defaults to list mode when localStorage has invalid data" test feeds
invalid JSON on purpose; createPersistentStore logs and swallows the parse
error, so its warning (with stack) was polluting CI output. Spy on
console.warn to silence it and assert it fired, matching the equivalent
test in createPersistentStore.test.ts.

src/widgets/SampleList/model/stores/layoutStore/layoutStore.test.ts

@@ -7,6 +7,7 @@ import {
     describe,
     expect,
     it,
+    vi,
 } from 'vitest';
 
 // Helper to flush Svelte effects (they run in microtasks)
@@ -69,12 +70,17 @@ describe('layoutStore', () => {
         });
 
         it('should default to list mode when localStorage has invalid data', async () => {
+            // createPersistentStore logs and swallows the parse error; silence
+            // the expected warn so it doesn't pollute test output, and assert it.
+            const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
             localStorage.setItem(STORAGE_KEY, 'invalid json');
 
             const { LayoutManager } = await import('./layoutStore.svelte');
             const manager = new LayoutManager();
 
             expect(manager.mode).toBe('list');
+            expect(warnSpy).toHaveBeenCalled();
+            warnSpy.mockRestore();
         });
 
         it('should default to list mode when localStorage has empty object', async () => {