Asks to demote or deactivate an Organization Admin (or steps the key's creator down).

Requires ManageUsers and an Idempotency-Key. The key's creator must be an active Organization Admin (a System Admin changes roles directly instead) and id an Organization Admin of the same organization with no other pending request. The target is notified (in the app and by e-mail) and can approve it (applies at once) or contest it until effectiveAt, 14 days from now; otherwise it is applied shortly after that. When id is the key's creator, it is their own approval and applies at once (200). Refused (409) when it would leave the organization with no active Organization Admin. Example: POST /api/v1/users/8f0c3c1e-2b6d-4c55-9a51-0d3f3c1b7e21/removal-requests { "action": "Demote", "newRole": "Manager" }.