pv lint --gate shapes: the GLOBAL NoFocus decline prints no report — by_shape/declines exist only on the per-shape path (#3610 follow-up) #4100

The problem

pv lint <dir> --gate shapes --format json refuses in two ways, and only one of them prints its evidence:

Measured with pv built from #3622's head f663d39e4, on a directory holding only ontology.yaml and empty-shape.yaml from tests/fixtures/ont/shapes-one-empty/:

exit=2   stderr: decline: NoFocus   stdout: 0 bytes

PMAT-3610 says all three answers must emit a parseable report with by_shape, and the file's own comment names the consumer: infra's SLK gate parses stdout whatever the exit code. On the second path that consumer gets nothing, so it scores the run UNMEASURED and can't name the shape.

The test that claimed to cover this did not

At #3622's head, the "lone-contract venue" tests used json-missing-ref. That fixture exits 3 (entity.ref … cannot be read, i.e. ExtractFailed) before decline() runs, and ont_extract_json.rs:128 asserts exactly that. So assert_ne!(code, 0) and extra().is_null() held for the wrong reason. #3622 replaces the fixture with a real all-vacuous corpus and records the asymmetry against this issue.

Done when

• The global NoFocus decline prints the same JSON document the per-shape path does: verdict: Unknown(NoFocus), by_shape with every <shape>=0, and declines naming each shape.
• The recorded-asymmetry test in shapes_vacuity.rs fails, as its message says it will, and is replaced by an assertion of the report.

Found by the #3622 re-review: all three lanes cited the fixture, and two cited the missing report. The exit-3 behaviour was re-measured by hand.

Not verified, recorded for whoever takes this: one lane says plain-text pv lint renders an armed vacuity as a green ✓ with no shape named. I could not reproduce that on the fixture, because validation fails first.