Configure Copilot coding agent instructions

[Copilot]

Configure GitHub Copilot coding agent per documented best practices.

Changes

.github/copilot-instructions.md - Comprehensive repository-wide instructions:

• Project structure (WPF app, CLI, NuGet client, tests)
• Build/test/package commands for .NET 8/9 multi-targeting
• C# conventions: explicit types, tabs, braces, trailing commas
• Architecture: MVVM, XML licenses, cryptographic signing
• Security: .private files contain signing keys, never commit

.github/workflows/copilot-setup-steps.yml - Environment setup:

• Moved from .github/ to .github/workflows/ (correct location)
• Changed runner: ubuntu-latest → windows-latest (WPF requires Windows)
• Updated actions: checkout@v6, setup-dotnet@v5
• Triggers on changes to workflow or instructions

Example Instruction Content

### Build
# Build main application (requires .NET 9)
dotnet build LicenseManagerX/LicenseManagerX.csproj --configuration Release --runtime win-x64

# Build NuGet client library (multi-target: .NET 8 and .NET 9)
dotnet build LicenseManager_12noon.Client/LicenseManager_12noon.Client.csproj --framework net8.0
dotnet build LicenseManager_12noon.Client/LicenseManager_12noon.Client.csproj --framework net9.0

### C# Code Style
- Prefer explicit type instead of var: `string s = new();`
- Use tabs (3 spaces equivalent), even in XAML
- Braces on single-line expressions
- Parentheses on binary conditionals: `if ((x > 0) && (y > 0))`

Copilot will now follow project conventions, use correct build commands, and understand Windows-specific requirements.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

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

• gh.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (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 the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>✨ Set up Copilot instructions</issue_title>
<issue_description>Configure instructions for this repository as documented in Best practices for Copilot coding agent in your repository.

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes ✨ Set up Copilot instructions #34

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.