[Studio][Bug] Prevent hidden instance selections from being batch-deleted

## Problem The managed-instance table keeps `selectedRowKeys` when the server-side search or type filter changes. A selected instance can disappear from the current table while remaining selected, and the batch-delete action still submits that hidden row key. ## Reproduction 1. Select instance A in the Studio instance inventory. 2. Change the search or type filter so A is no longer returned. 3. Use batch delete. 4. A is still included even though it is absent from the current table and confirmation context. ## Expected behavior Selection should be reconciled with the current inventory result whenever the query or refreshed result changes. The confirmation should identify the instances that will actually be deleted, and the request must not contain hidden stale keys. ## Suggested validation Add UI regression coverage for search changes, type-filter changes, and refreshes that remove a selected instance.