Add copilot instructions for XHarness repository

[Copilot]

This PR adds comprehensive GitHub Copilot instructions to help AI assistants understand and work effectively with the XHarness codebase. The instructions are located at .github/copilot-instructions.md as specified in the GitHub documentation.

What's Included

The copilot instructions provide detailed guidance on:

Project Overview & Architecture

• XHarness as a .NET command-line tool for cross-platform testing
• Two-layer architecture (tooling and application layers)
• Platform support: Android, Apple (iOS/tvOS/watchOS/xrOS/Mac Catalyst), WASM, WASI

Technical Knowledge

• Complete command structure: xharness [platform] [command] [options]
• All supported platform commands (Android, Apple, WASM, WASI)
• Standardized exit codes and error handling patterns
• System requirements and build procedures
• Key dependencies (ADB, mlaunch, Helix SDK)

Development Guidelines

• Platform-specific development knowledge
• Testing strategy (unit, integration, E2E tests)
• Common implementation patterns for commands
• Environmental variables and configuration options

Operational Knowledge

• Repository structure and file organization
• Troubleshooting guidelines for common issues
• Development workflow for bug fixes and new features
• Code quality standards and best practices

Self-Improvement Mechanism

• Instructions for autonomous updates when discovering new knowledge
• Emphasis on continuous improvement for effective operation
• Guidelines for maintaining accuracy and documentation structure

Purpose

These instructions enable AI assistants to:

• Understand the XHarness architecture and purpose
• Navigate the codebase effectively
• Follow established patterns and conventions
• Implement fixes and features autonomously
• Troubleshoot common issues
• Maintain and improve the instructions over time

The goal is to create an autonomous agent capable of solving issues, fixing problems, and adding new features while maintaining code quality and project standards.

Fixes #1427.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• 7tjvsblobprodcus341.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
• c78vsblobprodcus322.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
• d0svsblobprodcus381.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
• jd4vsblobprodcus366.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
• l49vsblobprodcus358.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
• uy6vsblobprodcus34.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
• vb4vsblobprodcus33.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
• yluvsblobprodcus367.vsblob.vsassets.io
  • Triggering command: dotnet build /home/REDACTED/work/xharness/xharness/XHarness.sln --verbosity minimal (dns block)
  • Triggering command: /home/REDACTED/work/xharness/xharness/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/REDACTED/work/xharness/xharness/artifacts/toolset/restore.proj /t:__WriteToolsetLocation /clp:ErrorsOnly;NoSummary /p:__ToolsetLocationOutputFile=/home/REDACTED/work/xharness/xharness/artifacts/toolset/10.0.0-beta.25320.5.txt (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

---

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[akoeplinger]

@copilot copy the copilot-setup-steps.yml https://github.com/dotnet/sdk/blob/main/.github/workflows/copilot-setup-steps.yml so that you have access to the vsblob.vsassets.io URLs.

[Copilot]

@copilot copy the copilot-setup-steps.yml https://github.com/dotnet/sdk/blob/main/.github/workflows/copilot-setup-steps.yml so that you have access to the vsblob.vsassets.io URLs.

I've copied the copilot-setup-steps.yml workflow from dotnet/sdk to .github/workflows/copilot-setup-steps.yml. This will allow access to the vsblob.vsassets.io URLs that were being blocked by firewall rules. The workflow includes the necessary environment variable COPILOT_AGENT_FIREWALL_ALLOW_LIST_ADDITIONS: "vsblob.vsassets.io" and follows the same pattern as the dotnet/sdk repository. Commit: d6aa4e1