feat: 段落分割 split_paragraphs（通用空行分词）

src/genesis/parsers/paragraph_splitter.py

@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+from typing import Any
+
+
+def _is_blank_row(row: list[Any]) -> bool:
+    return all(c is None or str(c).strip() == "" for c in row)
+
+
+def split_paragraphs(matrix: list[list[Any]]) -> list[tuple[int, int]]:
+    """以全空行为界的通用段落分割；返回 (start_row, end_row)（含端，0-based）。"""
+    paragraphs: list[tuple[int, int]] = []
+    start: int | None = None
+    for i, row in enumerate(matrix):
+        if not _is_blank_row(row):
+            if start is None:
+                start = i
+        else:
+            if start is not None:
+                paragraphs.append((start, i - 1))
+                start = None
+    if start is not None:
+        paragraphs.append((start, len(matrix) - 1))
+    return paragraphs