Administrator Reports - Metadata Query: "Whole Repository" and specific collections can be selected simultaneously in Collection Selector

[shernandez-dev]

Describe the bug

In the Administrator Reports > Metadata Query page, the "Whole Repository" option in the Collection Selector can be selected simultaneously with one or more specific collections. While the query logic appears to apply only to the specific collections selected, this behavior is visually confusing and semantically contradictory — selecting "Whole Repository" implies no collection filter should apply, yet specific collections can remain selected at the same time.

Observed on demo.dspace.org and sandbox.dspace.org using Google Chrome.

To Reproduce

1. Log in as an admin
2. Navigate to Reports → Metadata Query
3. Open the Collection Selector panel
4. Click "Whole Repository" to select it
5. Without deselecting it, click one or more specific collections
6. Both "Whole Repository" and the specific collection(s) appear selected simultaneously

Expected behavior

Selecting "Whole Repository" should automatically deselect any previously selected specific collections, and selecting any specific collection should automatically deselect "Whole Repository". The two options represent mutually exclusive filtering scopes and should not be selectable at the same time.

Related work

Identified while working on #5524 (Administrator reports + Metadata Queries: Communities appear in the Collection Selector but cannot be selected).