Rationale
A capability nobody has written a use case for is a capability nobody has shown a person
performing, and a use case with no scenario is prose. Coverage computed from the registry
and the use cases, with the policy saying which classes must be covered, turns "we should
document this" into a line doctor prints and finish refuses on.
Required behaviour
For every public command of the command registry, every guaranteed claim with a
responsibility, and every MCP tool the executable projects, majordomus usecase coverage
counts the active use cases that name it and the ones whose scenario runs it. The policy's
use_cases.coverage says, per class, whether a gap is required (a failure), advisory
(reported) or off. A draft use case never counts.
Failure behaviour
A violation is a FAIL finding under the category use-case naming the capability, the
counts and the scaffold command, and the command that found it exits 10; under finish
the policy key use_cases_covered refuses completion.
Verification
mj_validate_use_case_coverage decides it, dispatched from doctor, check, finish. The
behavioural case test/cases/94_use_cases.sh proves it, and CI runs that case.