fix(writer): 防静默丢章告警 + 占位符正则宽容化（大小写/全角冒号）

tests/test_docx_injector.py

@@ -48,6 +48,28 @@ def test_section_placeholder_replaced(tmp_path):
     assert "以下がDB表定义です。" in full_text
 
 
+def test_section_placeholder_case_insensitive(tmp_path):
+    # 宽容：docx 中锚点为 {{Section:id}}（大写键）也能注入
+    tpl = _make_template(tmp_path, "{{Section:db_design}}")
+    inj = DocxInjector(tpl)
+    out = inj.inject({"db_design": _section_blocks()}, {"doc_title": "概要設計書"})
+
+    full_text = "\n".join(p.text for p in out.paragraphs)
+    assert "{{Section:db_design}}" not in full_text
+    assert "3.1 テーブル一覧" in full_text
+
+
+def test_section_placeholder_fullwidth_colon(tmp_path):
+    # 宽容：docx 中锚点为 {{section：id}}（全角冒号）也能注入
+    tpl = _make_template(tmp_path, "{{section：db_design}}")
+    inj = DocxInjector(tpl)
+    out = inj.inject({"db_design": _section_blocks()}, {"doc_title": "概要設計書"})
+
+    full_text = "\n".join(p.text for p in out.paragraphs)
+    assert "{{section：db_design}}" not in full_text
+    assert "3.1 テーブル一覧" in full_text
+
+
 # ---------- 行内占位符替换 ----------
 
 def test_inline_meta_replaced(tmp_path):