Search Behaviour

### Current Behaviour

1. Enter a search term in the search field.
2. Select a note by clicking on it.
3. Clear the search by pressing "X" in the search field.
4. Notice that the note selected in step 2 is no longer selected.

### Expected Behaviour

1. Enter a search term in the search field.
2. Select a note by clicking on it.
3. Clear the search by pressing "X" in the search field.
4. Notice that the note selected in step 2 is still selected.

And

1. Create a note with no tags.
2. Select a tag in the tags list.
3. Enter a search term in the search field.
4. Select a note by clicking on it.
5. Clear the search by pressing "X" in the search field.
6. Notice that the note selected in step 2 is still selected and the tags list is now focused on "All Notes".

Reproduce the two search-and-selection flows in the macOS app, then trace how clearing the search field updates the selected note and tags list. Done means the selected note remains selected after clearing search, and the tags list returns to “All Notes” in the second scenario.

Written by the indexing model from the issue text.