VS 2026: Separate build and publish CI/CD pipelines

[csharpfritz]

Summary

Create independent CI/CD pipelines for the Visual Studio 2026 extension. The VS 2026 extension (C#/.NET/VSIX) must have completely separate build and publish workflows from the VS Code extension (TypeScript/.vsix).

Motivation

• Different languages and build systems (dotnet build vs npm)
• Different package formats (VSIX for VS Marketplace vs .vsix for VS Code Marketplace)
• Different marketplaces and publish tooling
• Independent release cadences — one extension shipping shouldn't block the other
• Per user directive from Jeffrey T. Fritz

Acceptance Criteria

• GitHub Actions workflow for building the VS 2026 extension on PR and push
  • Runs dotnet build / dotnet test for the vs2026/ project
  • Only triggers on changes to vs2026/** paths
  • Matrix: Windows (required), optionally Linux for service-layer unit tests
• GitHub Actions workflow for publishing the VS 2026 extension
  • Triggers on tag push (e.g., vs2026-v*) or manual dispatch
  • Builds release VSIX package
  • Publishes to Visual Studio Marketplace
  • Creates GitHub release with VSIX artifact attached
• Existing VS Code CI workflows remain untouched
• Path filters ensure VS Code changes don't trigger VS 2026 builds and vice versa
• Build status badges in README for both extensions

Implementation Details

Build Workflow (.github/workflows/vs2026-build.yml)

• Trigger: push and pull_request on vs2026/** paths
• Steps: checkout → setup-dotnet → restore → build → test → upload VSIX artifact
• Matrix: os: [windows-latest] (VS extensions require Windows for full VSIX packaging)

Publish Workflow (.github/workflows/vs2026-publish.yml)

• Trigger: tag vs2026-v* or workflow_dispatch
• Steps: checkout → setup-dotnet → build Release → package VSIX → publish to VS Marketplace → create GitHub release
• Secrets needed: VS_MARKETPLACE_PAT (separate from any VS Code marketplace token)

Path Isolation

# vs2026-build.yml
on:
  push:
    paths: ['vs2026/**']
  pull_request:
    paths: ['vs2026/**']

# Existing VS Code workflows should add path exclusions if not already filtered

Dependencies

• VS 2026: Project scaffold and VSIX configuration #43 (VS 2026 project scaffold must exist before CI can build it)

Size: M

Routing

Assigned to squad:livingston (DevOps/CI)