feat(skills): add clean-architecture skill

[lfr-ai]

Single self-contained SKILL.md enforcing Clean Architecture boundaries, the Dependency Rule, and layered separation of concerns across any language or framework.

Covers: 4-layer model, review checklist, domain purity red flags, anti-patterns, key patterns (Repository, Use Case, Composition Root), and severity guide.

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• I have read and followed the Guidance for submissions involving paid services.
• My contribution adds a new instruction, prompt, agent, skill, or workflow file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, agent, skill, or workflow with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.
• I am targeting the staged branch for this pull request.

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Description

Added clean-architecture skills for writing clean-architecture with Github-Copilot.

Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New plugin.
• New skill file.
• New agentic workflow.
• Update to existing instruction, prompt, agent, plugin, skill, or workflow.
• Other (please specify):

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Additional Notes

N/A

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

[github-actions]

🔍 Skill Validator Results

⚠️ Warnings or advisories found

Scope	Checked
Skills	1
Agents	1
Total	2
Severity	Count
---	---:
❌ Errors	0
⚠️ Warnings	1
ℹ️ Advisories	0

Summary

Level	Finding
ℹ️	Found 1 skill(s)
ℹ️	[clean-architecture] 📊 clean-architecture: 1,207 BPE tokens [chars/4: 1,394] (detailed ✓), 19 sections, 3 code blocks
ℹ️	[clean-architecture] ⚠ No numbered workflow steps — agents follow sequenced procedures more reliably.
ℹ️	✅ All checks passed (1 skill(s))

Full validator output

```text Found 1 skill(s) [clean-architecture] 📊 clean-architecture: 1,207 BPE tokens [chars/4: 1,394] (detailed ✓), 19 sections, 3 code blocks [clean-architecture] ⚠ No numbered workflow steps — agents follow sequenced procedures more reliably. ✅ All checks passed (1 skill(s)) ```

[aaronpowell]

This reads more like an instruction rather than a skill and it is very light on in terms of what guidance it is giving to the agent. Because of the complexity of clean architecture, I would expect any agent guidance to be detailed on how to implement the various boundaries, how to do command layers, etc.

[lfr-ai]

@aaronpowell Would you then recommend me to rewrite it into a more exhaustive setup along the lines of: https://github.com/github/awesome-copilot/tree/main/skills/security-review?

[aaronpowell]

Yes, a skill like that is a good pattern on handling a complex topic and providing the skill with deep knowledge and decision making processes.