feat(normalizer): receiver splitting

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

tools/import-normalizer/tests/test_persons.py

@@ -37,3 +37,16 @@ def test_parse_register_dedups_colliding_ids():
     ids = [p.person_id for p in people]
     assert ids == ["cram-hans-1", "cram-hans-2"]
     assert len(set(ids)) == 2
+
+def test_split_receivers():
+    assert persons.split_receivers("Eugenie Müller") == ["Eugenie Müller"]
+    assert persons.split_receivers("Walter und Eugenie de Gruyter") == ["Walter de Gruyter", "Eugenie de Gruyter"]
+    assert persons.split_receivers("Hedi und Tutu (Gruber)") == ["Hedi Gruber", "Tutu Gruber"]
+    assert persons.split_receivers("Clara u Familie") == ["Clara"]
+    assert persons.split_receivers("Eugenie de Gruyter geb. Müller") == ["Eugenie de Gruyter"]
+    assert persons.split_receivers("Herbert u Clara") == ["Herbert", "Clara"]
+    assert persons.split_receivers("") == []
+
+def test_find_known_last_name():
+    assert persons.find_known_last_name("Eugenie de Gruyter") == "de Gruyter"
+    assert persons.find_known_last_name("Clara") is None