Add empty state for searches with no results #550

Is your feature request related to a problem? Please describe.
When a search or filter returns no matching results, the results area is completely empty with no feedback to the user. This happens in both tabs.

Describe the solution you'd like
Show a clear empty state when no results match the current search or filters, consistently across both tabs.

For example, a message such as:

No results found. Try changing your search term or filters.

Describe alternatives you've considered
A simpler alternative would be to display only a short “No results found” message.

Additional context
The current search and filtering appear to work correctly; this request is about improving the zero-results experience by giving users clear feedback.