feat(normalizer): generate structured tags from Schlagwort + Inhalt fields

Adds tags.py module implementing a three-outcome heuristic:
- Individual-to-individual correspondence tags ("Clara an Herbert") → dropped
- Group/collective correspondence ("Clara an Kinder", "Walter an Geschwister") → Briefwechsel/<value>
- Semantic/event tags ("Brautbriefe", "Alltag", "zur Hochzeit") → Themen/<value>

Three correspondence patterns detected: space-an-space, starts-with-"an ",
and abbreviated-sender form ("Maria W.an Clara").

COLLECTIVE_TERMS in config.py extended with 17 plural/group relational terms
(söhne, brüder, schwiegereltern, cousinen, etc.) confirmed against the full Excel.

Also adds two-phase summary mining: every run emits review/tag-candidates.csv;
subsequent runs apply keywords from overrides/approved-themes.csv as Themen tags.

Outputs: canonical-documents.xlsx gets pipe-separated "Parent/Child" tag paths;
canonical-tag-tree.xlsx provides the full tag hierarchy for backend pre-import.

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

tools/import-normalizer/tests/test_normalize.py

@@ -62,3 +62,60 @@ def test_run_end_to_end(tmp_path):
     assert _matrix(out_dir / "canonical-persons.xlsx") == persons1
     assert (review_dir / "unparsed-dates.csv").read_text(encoding="utf-8") == unparsed1
     assert len(docs1) == 4  # header + 3 docs
+
+
+def test_tag_tree_output_emitted(tmp_path):
+    out_dir = tmp_path / "out"; review_dir = tmp_path / "review"
+    normalize.run(
+        document_workbook=_doc_wb(tmp_path), document_sheet="Familienarchiv",
+        person_workbook=_person_wb(tmp_path), person_sheet="Tabelle1",
+        out_dir=out_dir, review_dir=review_dir,
+        date_overrides={}, name_overrides={})
+    assert (out_dir / "canonical-tag-tree.xlsx").exists()
+
+
+def test_tag_candidates_review_emitted(tmp_path):
+    out_dir = tmp_path / "out"; review_dir = tmp_path / "review"
+    normalize.run(
+        document_workbook=_doc_wb(tmp_path), document_sheet="Familienarchiv",
+        person_workbook=_person_wb(tmp_path), person_sheet="Tabelle1",
+        out_dir=out_dir, review_dir=review_dir,
+        date_overrides={}, name_overrides={})
+    assert (review_dir / "tag-candidates.csv").exists()
+    text = (review_dir / "tag-candidates.csv").read_text(encoding="utf-8")
+    assert "candidate" in text and "count" in text
+
+
+def test_schlagwort_encoded_as_themen_in_documents(tmp_path):
+    out_dir = tmp_path / "out"; review_dir = tmp_path / "review"
+    normalize.run(
+        document_workbook=_doc_wb(tmp_path), document_sheet="Familienarchiv",
+        person_workbook=_person_wb(tmp_path), person_sheet="Tabelle1",
+        out_dir=out_dir, review_dir=review_dir,
+        date_overrides={}, name_overrides={})
+    wb = openpyxl.load_workbook(out_dir / "canonical-documents.xlsx")
+    ws = wb.active
+    header = [c.value for c in ws[1]]
+    tag_col = header.index("tags")
+    tag_values = [ws.cell(row=r, column=tag_col + 1).value for r in range(2, ws.max_row + 1)]
+    assert any(v and "Themen/Brautbriefe" in v for v in tag_values)
+    assert not any(v and v.strip() == "Brautbriefe" for v in tag_values)
+
+
+def test_approved_themes_applied(tmp_path):
+    themes_file = tmp_path / "approved-themes.csv"
+    themes_file.write_text("candidate\ngeschäftsreise\n", encoding="utf-8")
+    out_dir = tmp_path / "out"; review_dir = tmp_path / "review"
+    normalize.run(
+        document_workbook=_doc_wb(tmp_path), document_sheet="Familienarchiv",
+        person_workbook=_person_wb(tmp_path), person_sheet="Tabelle1",
+        out_dir=out_dir, review_dir=review_dir,
+        date_overrides={}, name_overrides={},
+        approved_themes_path=themes_file)
+    wb = openpyxl.load_workbook(out_dir / "canonical-documents.xlsx")
+    ws = wb.active
+    header = [c.value for c in ws[1]]
+    tag_col = header.index("tags")
+    tag_values = [ws.cell(row=r, column=tag_col + 1).value for r in range(2, ws.max_row + 1)]
+    # W-0001 has Inhalt "Geschäftsreise" — should get an extra Themen/geschäftsreise tag
+    assert any(v and "Themen/geschäftsreise" in v for v in tag_values)