feat: 段落分割 split_paragraphs（通用空行分词）

tests/test_paragraph_splitter.py

@@ -0,0 +1,25 @@
+from genesis.parsers.paragraph_splitter import split_paragraphs
+
+
+def test_empty_matrix():
+    assert split_paragraphs([]) == []
+
+
+def test_single_paragraph_no_empty_rows():
+    m = [["a", "b"], ["c", "d"]]
+    assert split_paragraphs(m) == [(0, 1)]
+
+
+def test_split_on_middle_empty_row():
+    m = [["a"], [], ["b"], ["c"], []]
+    assert split_paragraphs(m) == [(0, 0), (2, 3)]
+
+
+def test_trailing_empty_rows_no_extra_paragraph():
+    m = [["a"], [], [], []]
+    assert split_paragraphs(m) == [(0, 0)]
+
+
+def test_leading_empty_rows_start_at_first_nonempty():
+    m = [[], ["a"], [], ["b"]]
+    assert split_paragraphs(m) == [(1, 1), (3, 3)]