refactor(baoyu-post-to-x): replace hand-rolled markdown parser with marked ecosystem

Switch md-to-html from manual line-by-line parsing to marked + front-matter +
highlight.js + remark-cjk-friendly for robust markdown conversion with syntax
highlighting, proper CJK handling, and standard frontmatter parsing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/baoyu-post-to-x/scripts/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "baoyu-post-to-x-scripts",
+  "private": true,
+  "type": "module",
+  "dependencies": {
+    "front-matter": "^4.0.2",
+    "highlight.js": "^11.11.1",
+    "marked": "^15.0.6",
+    "remark-cjk-friendly": "^1.1.0",
+    "remark-parse": "^11.0.0",
+    "remark-stringify": "^11.0.0",
+    "unified": "^11.0.5"
+  }
+}