Returns a SUSPENDED Cryptographic Exchange to ACTIVE and republishes the linked
Capability Grant projection.

The body carries the optimistic-lock version and NOTHING ELSE.
Resume records no justification: restoring a capability generates no grievance
for the audit trail to answer, which is the PRD 224 exclusion this operation
inherits. A body that still carries reason is REFUSED with 400
rather than silently ignored - the request type has no such component and strict
deserialization is enabled - so a caller migrating off the retired shared
transition body learns that the value was never being recorded.

Authorization: requires scope admin.tenant.exchange.activate,

the same scope that governs activation (OQ-19). There is no .resume scope.