Iterates every active tenant in the deployment and creates a new tenant
algorithm policy row copied from the active deployment policy for tenants
that don't already have one. Idempotent — rerunning has no effect on tenants
that already have an active row.

This is the architect Phase 1.5 deployment-safety net for the Slice 6
fail-closed cutover in core-api. Invoke BEFORE promoting core-api Slice 6.

Scope: admin.policy.deployment.algorithm.write (platform-admin only).