Returns the measured blast radius of closing one tenant, in the three categories the closure cascade already uses: the assertions it removes, the subjects it disables, and the evidence it retains and renders permanently unusable.

Absent is not zero. A figure that could not be measured is ABSENT from the body; a figure that measured zero is PRESENT carrying 0. The two are distinguishable by shape alone — never by a status field beside a zero — because rendering them identically turns an availability failure into a confident falsehood about a tenant that is one irreversible click away from closure.

Coverage is per block. Each of the four measurement blocks carries its own status, its own measuredAt, and — when it is not COMPLETE — a reason drawn from a closed two-member vocabulary that discloses nothing about the failure. One block degrading leaves its siblings untouched, and a resolved tenant always answers 200: the envelope read is the floor.

No snapshot is claimed. The blocks are read sequentially, generatedAt is at or after every block's measuredAt, and the body carries no member asserting mutual consistency.

Authorization: Requires admin.tenant.delete — the scope of the operation this read precedes.