test(retrieval-gate): red -- rows 2 and 3 take their denominator from the run

PM's J10 and J8, the two attacks on the denominator, written as tests that
must refuse them.

J10 (`k = 32`): rows 1, 2, 3 and 6 all came back green at once and not one
label had become true. Rows 2 and 3 count against the misses and the withheld,
so a cut that delivers more broadly does not answer their question -- it
shrinks their denominator to the cases that were already honest. The three
fixtures that DECLARE class b are delivered under that cut, so their premise
is broken, and a broken premise is not an absence.

J8 (`--source-quota` off): every printed reason became true and row 3 read
`6 of 6 GREEN` while row 1 fell to 8 of 9. That reading is not a lie -- with
no quota there is no quota to name falsely -- but the row measured nothing,
because the label it judges was never printed.

3 red on an assertion about behaviour (GREEN where RED or NOT RUN is required,
and a broken premise counted as 0 of 0), 49 passed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_retrieval_gate.py

@@ -810,3 +810,69 @@ def test_j2b_row_eight_never_sums_the_two_granularities_into_its_headline(
         "1 of 1 at citation granularity, 2 of 2 at concept granularity" in detail
         for detail in row.details
     )
+
+
+def _attack(tmp_path: Path, **cut: object) -> dict[int, gate.Row]:
+    """Rows 1-6 remeasured under a cut this gate did not ship."""
+    cases, _ = gate.synthetic_cases(tmp_path / "bundles", FIXTURES)
+    with gate._wrap_cut(**cut):
+        remeasured = [gate.measure_case(case.question_set, case.bundles) for case in cases]
+        return {row.number: row for row in gate.deterministic_rows(remeasured)}
+
+
+def test_j10_a_wider_cut_does_not_make_rows_two_and_three_green(tmp_path: Path) -> None:
+    """PM's J10: `k = 32` took rows 1, 2, 3 and 6 green at once, and not one
+    label had become true -- the denominator of rows 2 and 3 IS the misses, so
+    delivering more broadly shrinks it to the cases that were already honest."""
+    rows = _attack(tmp_path, k=32)
+    assert rows[2].status == gate.RED, rows[2]
+    assert rows[3].status == gate.RED, rows[3]
+    # The three fixtures that declare class b are delivered under this cut, so
+    # their premise no longer holds -- and a broken premise counts against the
+    # row rather than leaving it.
+    assert any("premise" in detail for detail in rows[2].details), rows[2].details
+    assert rows[2].m >= 7
+
+
+def test_j8_removing_the_quota_leaves_row_three_unable_to_say_anything(
+    tmp_path: Path,
+) -> None:
+    """PM's J8: with `--source-quota` off every printed reason became true and
+    row 3 read `6 of 6 GREEN`, while row 1 fell to 8 of 9. The label this row
+    judges was not printed at all, so the row did not measure."""
+    rows = _attack(tmp_path, source_quota=None)
+    assert rows[3].status == gate.NOT_RUN, rows[3]
+    assert "quota" in rows[3].reason
+
+
+def test_a_forced_fixture_that_stops_missing_counts_against_row_two(
+    tmp_path: Path,
+) -> None:
+    """The fixed denominator, driven through a set file: a question that
+    DECLARES the class it forces and then comes back a hit has not been
+    classified -- its fixture's premise broke, and the row must carry it rather
+    than lose it."""
+    path, sha = _set_file(
+        tmp_path / "set.json",
+        set_id="row-two-premise",
+        bundle="positive",
+        questions=[
+            {
+                "id": "Z9",
+                "question": "Naar kontrolleres vinterberedskapen paa hytta?",
+                "expect_class": "b",
+                "fasit": [
+                    {
+                        "by": "concept",
+                        "value": "haandbok/vinterberedskap",
+                        "quote": "innen 1. november",
+                    }
+                ],
+            }
+        ],
+    )
+    case = gate.measure_case(gate.load_set(path, sha), _bundles(tmp_path))
+    assert [unit.hit for unit in case.units] == [True], "the fixture must HIT for this test"
+    row = gate.row_two([case])
+    assert (row.k, row.m, row.status) == (0, 1, gate.RED)
+    assert any("Z9" in detail and "premise" in detail for detail in row.details)