fix: 遗留清理（枚举同源/边界防御/断言补强）

tests/test_table_extractor.py

@@ -1,4 +1,4 @@
-from genesis.data_models import CellValue, ExcelTable, SheetType
+from genesis.data_models import CellValue, ExcelTable, ExtractionMethod, SheetType
 from genesis.parsers.merge_fill import forward_fill
 from genesis.parsers.table_extractor import column_letter, extract_table
 
@@ -37,4 +37,16 @@ def test_extract_table_basic():
     assert isinstance(first["ID"], CellValue)
     assert first["ID"].value == "1"
     assert first["ID"].provenance.sheet_name == "社員一覧"
-    assert first["ID"].provenance.column == "A"
+    assert first["ID"].provenance.column == "A"
+
+
+def test_extract_table_uses_enum_value():
+    matrix = [["ID"], ["1"]]
+    table = extract_table("社員", matrix, "f.xlsx", SheetType.FUNCTION)
+    assert table.extraction_method == ExtractionMethod.OPENPYXL.value
+
+
+def test_forward_fill_ignores_invalid_range():
+    matrix = [["A"], ["B"]]
+    assert forward_fill(matrix, [(0, 1, 2, 1)]) == matrix  # min_row=0 非法 → 不崩溃不改数据
+    assert forward_fill(matrix, [(9, 9, 9, 9)]) == matrix  # 越界 → 不崩溃