feat(segmentation): parse the adjudication state a plan already carries

tests/test_segmentation.py

@@ -531,3 +531,101 @@ def test_an_entry_without_an_anchor_keeps_todays_offset_behaviour() -> None:
     """The anchor is a capability, not a new requirement on authored plans."""
     sliced = slice_segments(SECTIONS, five_section_plan())
     assert [item.span for item, _ in sliced] == list(SPANS)
+
+
+# --- S5d: the adjudication state, parsed rather than discarded --------------
+#
+# The proposer has written `adjudicated: false` and `proposed_by` into every
+# plan since the tool shipped, and the parser dropped both on the floor: a
+# plan a human had ratified parsed into an object byte-identical to one nobody
+# had looked at. The whole design rests on that distinction -- a proposal must
+# never be replayable as an adjudication -- so it has to survive parsing
+# before anything downstream can act on it.
+#
+# Key names are B2's, verbatim (`docs/plan/office-intake.md` § 5). One
+# vocabulary from plan to frontmatter, so the profile that writes the marker
+# has nothing to translate and nothing to get wrong.
+
+
+def test_a_ratified_plan_and_an_unratified_one_are_distinguishable() -> None:
+    assert parse_segmentation_plan(plan(adjudicated=True)).adjudicated is True
+    assert parse_segmentation_plan(plan(adjudicated=False)).adjudicated is False
+
+
+def test_an_unmarked_plan_is_not_adjudicated() -> None:
+    """Absence is the safe reading: nobody ratified a plan that never said so.
+
+    The opposite default would let a plan predating the field replay as a
+    human judgement, which is the one thing this module exists to prevent.
+    """
+    payload = plan()
+    assert "adjudicated" not in payload
+    assert parse_segmentation_plan(payload).adjudicated is False
+
+
+def test_a_non_boolean_adjudicated_flag_is_refused() -> None:
+    """`"false"` is truthy. A string here would ratify a plan by accident."""
+    error = parse_fails(plan(adjudicated="false"))
+    assert error.code == "segmentation_plan_invalid"
+
+
+def test_the_proposer_identity_survives_parsing() -> None:
+    parsed = parse_segmentation_plan(plan(proposed_by="okf-propose-segments/1"))
+    assert parsed.proposed_by == "okf-propose-segments/1"
+    assert parse_segmentation_plan(plan()).proposed_by is None
+
+
+def test_a_per_entry_verdict_round_trips_with_its_dwell_time() -> None:
+    """Dwell time travels WITH the verdict, per B2.
+
+    A ratified flag carrying no per-item time is unfalsifiable, and it is the
+    same field that makes adjudication throughput measurable at all.
+    """
+    verdict = {
+        "adjudicated_by": "ktg",
+        "adjudicated_at": "2026-09-02T10:00:00Z",
+        "adjudication_dwell_s": 41,
+    }
+    parsed = parse_segmentation_plan(plan(entries=[entry(adjudication=verdict)]))
+    record = parsed.entries[0].adjudication
+    assert record is not None
+    assert record.adjudicated_by == "ktg"
+    assert record.adjudicated_at == "2026-09-02T10:00:00Z"
+    assert record.adjudication_dwell_s == 41
+    assert parse_segmentation_plan(plan()).entries[0].adjudication is None
+
+
+def test_a_verdict_missing_its_dwell_time_is_refused() -> None:
+    error = parse_fails(
+        plan(
+            entries=[
+                entry(
+                    adjudication={
+                        "adjudicated_by": "ktg",
+                        "adjudicated_at": "2026-09-02T10:00:00Z",
+                    }
+                )
+            ]
+        )
+    )
+    assert error.code == "segmentation_plan_invalid"
+    assert "adjudication_dwell_s" in str(error)
+
+
+def test_a_dwell_time_that_is_not_a_whole_number_of_seconds_is_refused() -> None:
+    """Integer seconds, per B2. `True` is an `int` in Python and is not one."""
+    for bad in ("41", 41.5, True):
+        error = parse_fails(
+            plan(
+                entries=[
+                    entry(
+                        adjudication={
+                            "adjudicated_by": "ktg",
+                            "adjudicated_at": "2026-09-02T10:00:00Z",
+                            "adjudication_dwell_s": bad,
+                        }
+                    )
+                ]
+            )
+        )
+        assert error.code == "segmentation_plan_invalid"