fix(normalizer): preserve trailing Bemerkung text after parent pattern

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tools/import-normalizer/tests/test_persons_tree.py

@@ -418,3 +418,16 @@ def test_parse_bemerkung_plain_remark():
     )
     assert rels == [] and unres == []
     assert notes == "Verfasserin der Cram-Chronik !!"
+
+
+def test_parse_bemerkung_sohn_with_trailing_remark():
+    _, idx = _register(
+        ("row_019", "Clara", "Cram", "de Gruyter"),
+        ("row_028", "Herbert", "Cram", None),
+    )
+    rels, unres, notes = persons_tree._parse_bemerkung(
+        "row_021", "Sohn v Clara Cram u Herbert Cram, nach Mexiko emigriert", idx
+    )
+    assert len(rels) == 2
+    assert unres == []
+    assert notes == "nach Mexiko emigriert"