feat: MIXED 完整段落解析（分割→每段最优解析）

tests/test_excel_parser.py

@@ -81,3 +81,58 @@ def test_mixed_sheet_holds_paragraphs():
     ms = MixedSheet(name="混合", paragraphs=[p1, p2])
     assert ms.name == "混合"
     assert [p.kind for p in ms.paragraphs] == ["table", "free_text"]
+
+
+def test_parse_mixed_sheet_segmented(tmp_path):
+    wb = new_workbook({
+        "混合": [
+            ["機能ID", "機能名"],
+            ["F101", "社員登録"],
+            ["F102", "退職処理"],
+            [],
+            ["・改修ポイント：F102 追加バリデーション"],
+            ["■対象画面：SC001"],
+        ],
+    })
+    path = save_workbook(tmp_path, wb)
+    result = ExcelParser().parse(path)
+    assert result.mixed, "混合 sheet 应产产出 mixed 段落"
+    ms = result.mixed[0]
+    assert ms.name == "混合"
+    kinds = [p.kind for p in ms.paragraphs]
+    assert "table" in kinds and "free_text" in kinds
+    # 表格段无碎片污染：table 段应含 2 数据行，机能ID 首行为 F101
+    tbl = [p.table for p in ms.paragraphs if p.kind == "table"][0]
+    assert tbl is not None and len(tbl.rows) == 2
+    assert tbl.rows[0]["機能ID"].value == "F101"
+    # 自由文本段捕获碎片
+    ft = [p for p in ms.paragraphs if p.kind == "free_text"][0]
+    assert "改修ポイント" in (ft.text or "")
+
+
+def test_parse_mixed_sheet_formatting_in_mid_segment(tmp_path):
+    # 表格段不在物理行 0（自由文本段在前），数据行 F101 设取消线 —— 锁住 formatting_map 坐标错位
+    from copy import copy
+    from openpyxl import Workbook
+    wb = Workbook()
+    ws = wb.active
+    ws.title = "混合"
+    data = [
+        ["■はじめに"], ["前提説明"], [],
+        ["機能ID", "機能名"], ["F101", "社員登録"], ["F102", "退職処理"],
+        [], ["・改修ポイント"],
+    ]
+    for r, row in enumerate(data, start=1):
+        for c, v in enumerate(row, start=1):
+            if v:
+                ws.cell(row=r, column=c, value=v)
+    font = copy(ws.cell(row=5, column=1).font)  # F101 所在物理行（第 5 行）
+    font.strike = True
+    ws.cell(row=5, column=1).font = font
+    path = save_workbook(tmp_path, wb)
+    result = ExcelParser().parse(path)
+    ms = result.mixed[0]
+    tbl = [p.table for p in ms.paragraphs if p.kind == "table"][0]
+    cv = tbl.rows[0]["機能ID"]  # F101
+    assert cv.formatting is not None
+    assert cv.formatting.strikethrough is True