Put user-defined project guidelines at the top of the generated guidelines file

[imliam]

Potentially solves #146

Just raising this as an easy merge if you agree that user guidelines should take more precedence than the Boost presets, but happy to do another approach if liked

[Copilot]

Pull Request Overview

This PR changes the order in which guidelines are loaded, placing user-defined project guidelines at the top of the generated guidelines file instead of at the bottom. This gives user guidelines higher precedence over Boost presets.

• Move user guideline loading from the end to the beginning of the collection process
• Maintain existing logic for all other guideline types (foundation, boost, framework-specific, etc.)

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.
You can also share your feedback on Copilot code review for a chance to win a $100 gift card. Take the survey.}