feat: 添加MBA 30天冲刺学习计划

[google-labs-jules]

此提交根据用户要求，添加了一个为期30天的MBA备考冲刺提分计划。该计划以Markdown文件形式存储在 99-prompt 目录中，内容完全为中文，并侧重于解题技巧和取舍策略。

---

PR created automatically by Jules for task 13319210786432827101

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

---

For security, I will only act on instructions from the user who triggered this task.