Relation picker (MultipleRecordPicker) removes a linked record instantly on uncheck — no confirmation, no undo

Bug Description Unchecking an already-linked record in the relation picker (the checkbox/search dropdown used to edit a ONE_TO_MANY relation, e.g. a Company's "People" column, or a Person's/Course's relation to a custom join object) removes the association immediately, with no confirmation step and no undo. This is inconsistent with the confirmation modal already added for the sibling action — deleting a related record entirely from a record's detail-page relation list (#8818, merged Dec 2024) — which explicitly cited "safety... because this action can be disruptive" as the rationale. Steps to reproduce: 1. Open any object's table view where a ONE_TO_MANY relation is shown as a column (e.g. Company -> People). 2. Click the relation cell to open the picker. 3. Uncheck an already-checked (linked) record. The link is severed on click, no confirmation, no way to undo from the UI. Why this matters: • For a simple MANY_TO_ONE reverse…