Enhancement: Compare newly fetched boundaries with previous items in breadcrumbs

[coderabbitai]

Background

When fetching new boundary data for breadcrumbs, we should implement a comparison with previously displayed items to ensure optimal updates and maintain UI consistency.

Current Behavior

Currently, in debouncedItemsFetch, new boundary data directly replaces the previous items without any comparison:

breadcrumbsItemsAtom(ctx, response?.features ?? null);

Proposed Enhancement

Implement a comparison mechanism between newly fetched boundaries and existing items before updating the breadcrumbs state.

References

• Original PR discussion: fix(20960): reserve 40px height for breadcrumbs #985 (comment)
• Related file: src/features/breadcrumbs/atoms/breadcrumbsItemsAtom.ts