Update CSharpExpert agent with .NET and C# version info

[mihsoft]

Added information about familiarity with .NET 10 and C# 14. Confirmed correct interactions with Gemini 3 Pro (Preview)

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution adds a new instruction, prompt, or chat mode 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, or chat mode with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.

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Description

Most models were built prior to C# 13 and C# 14 and NET 9 and NET 10, this instructs the agent to learn these first and obtain the necessary context to provide up-to-date recommendations

Type of Contribution

• New instruction file.
• New prompt file.
• New chat mode file.
• New collection file.
• Update to existing instruction, prompt, chat mode, or collection.
• Other (please specify):

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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.

[Copilot]

Pull request overview

This PR updates the CSharpExpert agent to declare familiarity with .NET 10 and C# 14, including reference URLs to Microsoft documentation for these versions.

Key Changes:

• Added statement indicating familiarity with .NET 10 and C# 14
• Included reference URLs to Microsoft documentation for .NET 9, .NET 10, C# 13, and C# 14

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[codemillmatt]

Thanks for this one @mihsoft . I'm wondering if it'd make sense to include a reference to the MS Learn MCP tooling in this? Thoughts?