fix: keep YAML frontmatter description unescaped

The previous regex over-applied: it escaped A* to A\* inside the
description value of the YAML frontmatter, which js-yaml rejects as
'unknown escape sequence' and which broke the Astro site build (and
the Netlify deploy preview).

scripts/make.py's metaext strips frontmatter before md2tex runs, so
the asterisk in description never reaches the markdown pipeline and
doesn't need escaping. Body asterisks remain escaped.

Author: Gavin-WangSC

src/content/blog/2026-02-13/index.md

@@ -2,7 +2,7 @@
 title: "路径规划算法优化"
 author: "杨岢瑞"
 date: "Feb 13, 2026"
-description: "路径规划算法优化，从基础 A\*到 JPS 前沿实践"
+description: "路径规划算法优化，从基础 A*到 JPS 前沿实践"
 latex: true
 pdf: true
 ---