feat(normalizer): unresolved-names report + fix ambiguous-pair over-flagging

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tools/import-normalizer/tests/test_documents.py

@@ -93,10 +93,17 @@ def test_resolve_one_override_increments_hits():
     assert name == "Eugenie de Gruyter"   # display comes from the alias index
     assert ctx.override_hits == 1
 
-def test_ambiguous_space_pair_flagged_not_split():
-    # US-PERS-02 AC4: "Ella Anita" is kept as one provisional + flagged, never guessed into two.
-    ctx = _ctx()
+def test_ambiguous_pair_recorded_in_unresolved():
+    people = persons.parse_register([{"last_name": "de Gruyter", "first_name": "Walter"}])
+    ctx = persons.ResolutionContext(persons.AliasIndex(people), name_overrides={},
+                                    given_names={"ella", "anita"})
     raw = documents.RawRow(source_row=7, index="C-0200", sender="", receivers="Ella Anita")
     doc = documents.to_canonical(raw, ctx, date_overrides={})
-    assert len(doc.receiver_person_ids) == 1          # not split
-    assert any(part == "Ella Anita" for _, part, _ in ctx.ambiguous)
+    assert len(doc.receiver_person_ids) == 1   # not split — one provisional
+    assert any(name == "Ella Anita" and cat == "ambiguous_pair" for name, cat, _ in ctx.unresolved)
+
+def test_resolvable_first_surname_pair_not_unresolved():
+    ctx = persons.ResolutionContext(persons.AliasIndex([]), name_overrides={},
+                                    given_names={"ella", "anita"})
+    ctx.resolve_one("Mieze Schefold", source_row=1)   # surname is not a given name
+    assert ctx.unresolved == []                        # RESOLVABLE -> not recorded