Epic: Secure Identity Provider (IDP) Management & Email Continuity

[JoseSzycho]

Overview

We need to overhaul how users manage their linked identities to prevent "orphaned" accounts. Currently, deleting a linked IDP can leave a user with an email address that is no longer verified by an external provider, or worse, an account with no valid email at all.

This epic tracks the temporary UI restriction and the subsequent implementation of a robust backend deletion flow.

Objectives

1. Prevent Data Corruption: Stop users from accidentally breaking their account state via the UI.
2. Automated Continuity: Implement logic to automatically transition a user's primary email to a remaining identity upon deletion.
3. Safety Constraints: Prevent the removal of the "last valid source of truth" for a user's email address.