VS 2026: Project scaffold and VSIX configuration

[csharpfritz]

Description

Create the foundational C# project structure and VSIX configuration for the VS 2026 extension using the new VisualStudio.Extensibility SDK (not legacy VSSDK). This is the base upon which all other VS 2026 features depend.

Acceptance Criteria

• C# project created in vs2026/ or src-vs2026/ folder
• Solution file (.sln) configured with NuGet package references
• VSIX manifest configured with extension metadata
• VisualStudio.Extensibility SDK packages installed and referenced
• Extension activation and command registration working
• Project builds successfully with no errors
• GitHub Actions CI/CD recognizes VS 2026 project and runs builds

Implementation Details

Project Structure

Create folder: vs2026/ (or src-vs2026/ if preferred for consistency)

Suggested layout:

vs2026/
  SquadUI.VS2026.csproj
  Properties/
    AssemblyInfo.cs
  Extension.cs          (entry point)
  SquadUI.VS2026.sln

VSIX Configuration

• Create extension manifest with metadata:
  • Display name: "Squad UI - Visual Studio 2026"
  • Description: "Visualize your Squad AI team members and their tasks"
  • Version: 0.1.0
  • Minimum VS 2026 version requirement
• Configure command table (*.vsct) or command registration via VisualStudio.Extensibility API

VisualStudio.Extensibility SDK Setup

• Install Microsoft.VisualStudio.Extensibility NuGet package (v17.x or latest)
• Do NOT use legacy VSSDK (Microsoft.VisualStudio.SDK)
• Configure MEF component registration for extension services
• Set up extension entry point with proper async activation

Extension Activation

• Implement IExtensionService or equivalent activation interface
• Register with MEF ComponentPartCatalog
• Basic "Hello VS 2026" command to verify activation works
• No tool windows yet (that's Issue Define data models for squad members and tasks #2)

Size Estimate

M (Medium) — 4-6 hours

Priority

P1 (Critical Path)

Dependencies

• None — this is the foundation

Notes

• Reference Microsoft's VisualStudio.Extensibility sample projects for project structure
• VS Code extension lives in src/ as TypeScript; VS 2026 extension is entirely separate C# codebase
• Both extensions share the .ai-team/ file format and layout, but have independent implementations
• Assigned to: squad:virgil (VS 2026 Extension Dev)

[github-actions]

📋 Assigned to Virgil (VS Extension Dev (VS 2026))

Issue: #43 — VS 2026: Project scaffold and VSIX configuration

Virgil will pick this up in the next Copilot session.

For Copilot coding agent: If enabled, this issue will be worked automatically.
Otherwise, start a Copilot session and say:
Virgil, work on issue #43