fix(emit): a contracted floor that ran nothing is not a pass

[khymerao]

Fixes defect 3a of #15.

The defect, from the invariants

record discards the floor's own fail-closed verdict when the floor resolved to no command.

run_test_floor initialises every result as {"passed": false, "merge_blocked": true} and documents "merge_blocked is True on any floor FAILURE (Iron-Invariant #6)". _cmd_test_floor emits exactly that document on TestContractError. ADR 0003 relies on it: "run_test_floor is already merge-blocking and already fail-closed on an empty command."

The fast path's own consumer honours it - build_review_spec gate 1 refuses on not passed or merge_blocked. Engine C's consumer does not: _job_result_from reads the floor only through _tests_block_from_floor, which returns None when checks[] carries no checker, so merge_blocked: true is never consulted and the job keeps the scope verdict's success. Same floor document, two consumers, opposite conclusions.

ADR 0003 Consequences: "A job reporting no test command at all is a FAIL, not a pass." agents/spec-reviewer.md enforces that in prose (ISSUE: NO_TEST_EVIDENCE - "Silence is not success; an absent record is exactly what a worker that skipped the step looks like"). Dogfood 14 moved the red half of the rule from prose into record, because "the tests block is the fourteenth mechanism this project built and left without a consumer". This closes the empty half at the same layer, for the same reason.

Frequency, stated honestly

Never observed. 0 of 198 recorded results in this repository and 0 of 17 in the reporting project show success with no tests block under a contracted manifest. The run in #15 was caught by the red-floor rule: task-4-wire was status: blocked, tests.exit_code: 1 - its floor did run and went red.

This is a latent fail-open found by reading the code, not a reproduced defect. An earlier revision of this PR claimed otherwise on the strength of a narrative I had not checked against the run record; that claim is withdrawn.

The rule

if status == "success" and tests_block is None and contract_declared:
    status = "error" if tests is None else "blocked"

• The predicate is the manifest's declaration, not the resolved slice. contract is read from jobs/<id>.test-contract.json, which does not exist precisely when resolution failed - the reachable case (a manifest declaring impacted_map with no full_command passes the validator, then the resolver raises and no slice is written). Keying on the slice would leave that hole open.
• tests is None is error, not blocked. No floor document at all means fastpath-run.py was absent or died before writing JSON - the machinery is broken, which is a different taxonomy from a refused job.
• The refusal carries the floor's own reasons into summary. It previously fell back to the job title, which is a refusal for an unstated reason - the failure mode the gate-receipt code itself warns about.

Not changed

An uncontracted manifest still records success with no tests object - "no floor at all is not a failure" (dogfood 14), and the emitter's own note that "the worker runs no tests and reports no tests object, which is the documented honest outcome, not a silent zero".

No false positives for docs-only jobs. resolve_test_commands puts floor_command first at every tier and raises on an empty set, so a docs-only change at SCOPED/DIRECT/FULL still resolves to [floor_command] and produces a checks[] entry. A job whose floor legitimately has nothing impacted to run still has a floor, so tests_block is non-None and this rule cannot fire.

Tests

532/532 (was 526/526 on main). Six rows: a contracted floor that resolved to no command is blocked; it carries no fabricated tests block; the refusal states the floor's own reason; a declared contract whose slice is missing is still caught; no floor document at all is error; an uncontracted job still passes.

Mutation-checked - disabling the rule fails four of the six.

Full scripts/*.py --selftest sweep, lint-frontmatter, rules-lint green locally.

Note on CI

The red Full test suite is tests/test-native-points.sh, which fails 2 PRECOMPACT rows on a clean main too - the hardcoded-date time bomb that #11 fixes. Not from this branch.

[khymerao]

Folded into #13, which now carries both halves of the same story: what a test_contract command means to its executor, and what the floor document means to its consumer. They key on the same document and should be reviewed and bisected together.

Nothing is dropped - the empty-floor rule, its six selftest rows and the corrections from review (predicate on the manifest's declaration rather than the resolved slice; error when no floor document exists; the floor's own reasons carried into summary) are all in #13 unchanged.