fix: _wrap_chinese crash on mixed-width punctuation

_image_generator.py _wrap_chinese 当标题中只有 ASCII 标点
(如 ( ) ?) 而无全角标点时，max() 收到空序列崩溃。

修复：try-except 兜底 + 补充 ASCII 标点到断点列表

scripts/image_generator.py

@@ -109,7 +109,10 @@ def _wrap_chinese(text: str, chars_per_line: int = 14) -> List[str]:
     while len(remainder) > chars_per_line:
         chunk = remainder[:chars_per_line]
         # 尝试在最后一个标点处断开
-        cut = max(chunk.rfind(c) + 1 for c in ("，", "、", "。", "！", "？", "：", "；", "）", " ", "—") if c in chunk[:-1])
+        try:
+            cut = max(chunk.rfind(c) + 1 for c in ("，", "、", "。", "！", "？", "：", "；", "）", " ", "—", ",", ".", "!", "?", ":", ";", ")", "(", "-") if c in chunk[:-1])
+        except ValueError:
+            cut = 0
         if cut <= 0:
             cut = chars_per_line
         lines.append(remainder[:cut].strip())