feat: add bulk move recipes endpoint

Add new move_recipes_bulk endpoint to handle moving multiple recipes simultaneously. This improves efficiency when reorganizing recipe collections by allowing batch operations instead of individual moves.

- Add move_recipes_bulk handler method with proper error handling
- Register new POST /api/lm/recipes/move-bulk route
- Implement bulk move logic in persistence service
- Validate required parameters (recipe_ids and target_path)
- Handle common error cases including validation, not found, and server errors

tests/frontend/core/appCore.test.js

@@ -252,13 +252,13 @@ describe('AppCore initialization flow', () => {
     expect(onboardingManager.start).not.toHaveBeenCalled();
   });
 
-  it('skips bulk setup when viewing recipes', async () => {
+  it('initializes bulk setup when viewing recipes', async () => {
     state.currentPageType = 'recipes';
 
     await appCore.initialize();
 
-    expect(bulkManager.initialize).not.toHaveBeenCalled();
-    expect(BulkContextMenu).not.toHaveBeenCalled();
-    expect(bulkManager.setBulkContextMenu).not.toHaveBeenCalled();
+    expect(bulkManager.initialize).toHaveBeenCalledTimes(1);
+    expect(BulkContextMenu).toHaveBeenCalledTimes(1);
+    expect(bulkManager.setBulkContextMenu).toHaveBeenCalledTimes(1);
   });
 });