fix(docs): add missing resolveComponent import in code-highlighter demo

[cc-hearts]

🤔 This is a ...

• 🆕 New feature
• 🐞 Bug fix
• 📝 Site / documentation improvement
• 📽️ Demo improvement
• 💄 Component style improvement
• 🤖 TypeScript definition improvement
• 📦 Bundle size optimization
• ⚡️ Performance optimization
• ⭐️ Feature enhancement
• 🌐 Internationalization
• 🛠 Refactoring
• 🎨 Code style optimization
• ✅ Test Case
• 🔀 Branch merge
• ⏩ Workflow
• ⌨️ Accessibility improvement
• ❓ Other (about what?)

🔗 Related Issues

• N/A. Found during a docs demo code audit.

💡 Background and Solution

The code-highlighter demo (packages/docs/src/pages/markdown/demo/code-highlighter.vue) called resolveComponent("ax-code-highlighter") without importing resolveComponent from vue.

It only worked inside the docs app because unplugin-auto-import is configured with imports: ["vue", ...], which auto-imports resolveComponent globally. However, the demo code is displayed to users as a copyable example, so anyone copying it would hit resolveComponent is not defined.

This is inconsistent with the sibling gpt-vis demo (packages/docs/src/pages/components/bubble/demo/gpt-vis.vue), which imports resolveComponent explicitly.

Solution: Add resolveComponent to the from "vue" import block, placed after ref to match the gpt-vis demo convention. The displayed demo source (generated into public/markdown/*.md) regenerates from this .vue file, so a single source fix covers all rendered examples (examples.md, rich-text.md and their -en variants).

📝 Change Log

Language	Changelog
🇺🇸 English	Add the missing resolveComponent import to the code-highlighter demo so the copyable example runs without the docs app's auto-import setup.
🇨🇳 Chinese	为 code-highlighter demo 补充缺失的 resolveComponent 导入，使展示的可复制示例在脱离文档站点的 auto-import 配置时也能正常运行。