feat: surface disputed extracted values to critic and specialist prompts

tests/agents/test_disputes.py

@@ -40,3 +40,30 @@ def test_annotate_clusters_writes_disputed_attributes():
     assert annotate_clusters(clusters) == 1
     assert clusters[0]["disputed_attributes"][0]["attribute"] == "stud_pack_size"
     assert "disputed_attributes" not in clusters[1]
+
+
+def test_slim_clusters_preserves_disputed_attributes():
+    from backend.pipeline._serialize import slim_clusters
+    cluster = {"key": "c1", "assertions": [],
+               "disputed_attributes": [{"attribute": "a", "values": ["1", "2"],
+                                         "assertion_ids": ["x", "y"]}]}
+    slim = slim_clusters([cluster])[0]
+    assert slim["disputed_attributes"][0]["values"] == ["1", "2"]
+
+
+def test_find_disputes_handles_none_and_zero_values():
+    # None value/attribute -> skipped; numeric 0 is a real value, not blank
+    assertions = [
+        {"id": "a1", "attribute": "count", "value": 0},
+        {"id": "a2", "attribute": "count", "value": 1},
+        {"id": "a3", "attribute": None, "value": "x"},
+        {"id": "a4", "attribute": "count", "value": None},
+    ]
+    disputes = find_disputes(assertions)
+    assert len(disputes) == 1
+    assert disputes[0]["values"] == ["0", "1"]
+
+
+def test_find_disputes_empty_input():
+    assert find_disputes([]) == []
+    assert annotate_clusters([]) == 0