feat: data_models 扩展 MixedParagraph/MixedSheet（段落容器）

src/genesis/data_models.py

@@ -1,8 +1,8 @@
 from __future__ import annotations
 
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from enum import Enum
-from typing import Any
+from typing import Any, Literal
 
 
 class SheetType(Enum):
@@ -222,4 +222,21 @@ class StructuredSource:
     rule_docs: list[RuleDocument]
     image_analyses: list[ImageAnalysis]
     existing_system: ExistingSystemInfo | None
-    comments: list[CellComment]
+    comments: list[CellComment]
+
+
+@dataclass
+class MixedParagraph:
+    """混合 sheet 的一个段落（表格或自由文本）"""
+    kind: Literal["table", "free_text"]
+    matrix: list[list[Any]] | None = None    # 该段原始矩阵（调试/重现）
+    table: ExcelTable | None = None           # kind="table" 时填充
+    text: str | None = None                   # kind="free_text" 时填充（段全文）
+    source_range: tuple[int, int] | None = None  # (first_row, last_row) 矩阵 0-based
+
+
+@dataclass
+class MixedSheet:
+    """混合 sheet 的段落集合"""
+    name: str
+    paragraphs: list[MixedParagraph] = field(default_factory=list)