Identity Platform: Auth0, Icelandic eID, SSO

The platform needed one Auth0 connection per tenant, Icelandic eID federation, and single sign-on across many subdomains. The hard part was moving 120 of those connections from "Auth0 owns the users" to "WordPress is the source of truth" without breaking anyone's login. I wrote a Node.js tool that backed up before it mutated, ran dry runs, required typed confirmation, used deep-merge payloads, backed off on rate limits, and kept an audit log. It flipped 120 connections in 84 seconds with zero failures. A deep-merge fix caught in testing prevented silently wiping every connection's login scripts.