feat: Add WeChat posting skill and update marketplace.json

skills/post-to-wechat/SKILL.md

@@ -0,0 +1,54 @@
+---
+name: post-to-wechat
+description: Post content to WeChat Official Account (微信公众号). Supports both article posting (文章) and image-text posting (图文).
+---
+
+# Post to WeChat Official Account (微信公众号)
+
+Post content to WeChat Official Account using Chrome CDP automation.
+
+## Quick Usage
+
+### Image-Text (图文) - Multiple images with title/content
+
+```bash
+# From markdown file and image directory
+npx -y bun ./scripts/wechat-browser.ts --markdown article.md --images ./images/
+
+# With explicit parameters
+npx -y bun ./scripts/wechat-browser.ts --title "标题" --content "内容" --image img1.png --image img2.png --submit
+```
+
+### Article (文章) - Full markdown with formatting
+
+```bash
+# Post markdown article
+npx -y bun ./scripts/wechat-article.ts --markdown article.md --theme grace
+```
+
+## References
+
+- **Image-Text Posting**: See `references/image-text-posting.md` for detailed image-text posting guide
+- **Article Posting**: See `references/article-posting.md` for detailed article posting guide
+
+## Prerequisites
+
+- Google Chrome installed
+- `bun` runtime (via `npx -y bun`)
+- First run: log in to WeChat Official Account in the opened browser window
+
+## Features
+
+| Feature | Image-Text | Article |
+|---------|------------|---------|
+| Multiple images | ✓ (up to 9) | ✓ (inline) |
+| Markdown support | Title/content extraction | Full formatting |
+| Auto title compression | ✓ (to 20 chars) | ✗ |
+| Content compression | ✓ (to 1000 chars) | ✗ |
+| Themes | ✗ | ✓ (default, grace, simple) |
+
+## Troubleshooting
+
+- **Not logged in**: First run opens browser - scan QR code to log in, session is preserved
+- **Chrome not found**: Set `WECHAT_BROWSER_CHROME_PATH` environment variable
+- **Paste fails**: Check system clipboard permissions