fix(normalizer): don't coerce boolean cells to 1/0

Add bool guard before the int branch in _cell_to_str so True/False
cells are preserved as "True"/"False" instead of "1"/"0". Add two
regression tests covering the fix and missing-sheet error.

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

tools/import-normalizer/ingest.py

@@ -7,6 +7,8 @@ import openpyxl
 def _cell_to_str(value) -> str:
     if value is None:
         return ""
+    if isinstance(value, bool):   # bool is a subclass of int — handle before the int branch
+        return str(value)
     if isinstance(value, datetime.datetime):
         return value.date().isoformat()
     if isinstance(value, datetime.date):

tools/import-normalizer/tests/test_ingest.py

@@ -34,3 +34,13 @@ def test_build_header_map_collapses_whitespace_and_case():
 def test_build_header_map_missing_required_raises():
     with pytest.raises(ValueError, match="index"):
         ingest.build_header_map(["Box", "Ort"], {"box": "box", "ort": "location"}, required={"index"})
+
+def test_read_sheet_bool_not_coerced_to_int(tmp_path):
+    path = _make_workbook(tmp_path, "S", [["Flag"], [True], [False]])
+    rows = ingest.read_sheet(path, "S")
+    assert rows[1] == ["True"] and rows[2] == ["False"]   # not "1"/"0"
+
+def test_read_sheet_missing_sheet_raises(tmp_path):
+    path = _make_workbook(tmp_path, "S", [["A"]])
+    with pytest.raises(ValueError, match="not found"):
+        ingest.read_sheet(path, "Nope")