feat: Automatic LSP configuration for Copilot CLI (#74)

[GordonBeeming]

Automatically configure Language Server Protocol (LSP) servers in container
images so Copilot CLI gets code intelligence out of the box.

• Add lsp-typescript snippet: installs typescript-language-server for all images
• Add lsp-csharp snippet: installs csharp-ls for dotnet images with .NET 10 SDK
  (csharp-ls v0.22.0 only ships net10.0 TFM, so dotnet-8/9 excluded)
• Add lsp-rust snippet: adds rust-analyzer via rustup for rust images
• Add lsp-golang snippet: installs gopls for golang images
• Each snippet writes a config fragment to /etc/copilot/lsp-config.d/
• Entrypoint merges fragments into ~/.copilot/lsp-config.json at startup
  (skipped if user provides their own)
• Update images.json and regenerate all Dockerfiles

Closes #74

Co-authored-by: Claude Opus 4.6 (1M context) noreply@anthropic.com
Co-authored-by: GitButler gitbutler@gitbutler.com

[Copilot]

Pull request overview

Adds automatic, image-baked LSP server configuration for GitHub Copilot CLI by installing language servers in relevant container images and generating a unified ~/.copilot/lsp-config.json at container startup from drop-in fragments.

Changes:

• Add Docker snippet(s) to install LSP servers (TypeScript, Rust, Go, C#) and write per-language config fragments to /etc/copilot/lsp-config.d/.
• Update the container entrypoint to merge fragment JSON files into ~/.copilot/lsp-config.json when the user hasn’t provided their own.
• Update docker/images.json to include the new snippets across image variants and regenerate Dockerfiles.

Reviewed changes

Copilot reviewed 7 out of 17 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
docker/snippets/lsp-typescript.Dockerfile	Installs TypeScript LSP and writes TypeScript LSP config fragment.
docker/snippets/lsp-rust.Dockerfile	Installs Rust Analyzer and writes Rust LSP config fragment.
docker/snippets/lsp-golang.Dockerfile	Installs gopls and writes Go LSP config fragment.
docker/snippets/lsp-csharp.Dockerfile	Installs csharp-ls and writes C# LSP config fragment.
docker/shared/entrypoint.sh	Merges /etc/copilot/lsp-config.d/*.json into ~/.copilot/lsp-config.json on startup if not user-provided.
docker/images.json	Adds LSP snippets to the relevant image definitions so they’re included in generated Dockerfiles.
docker/generated/Dockerfile.default	Regenerated to include TypeScript LSP snippet.
docker/generated/Dockerfile.playwright	Regenerated to include TypeScript LSP snippet.
docker/generated/Dockerfile.dotnet	Regenerated to include TypeScript + C# LSP snippets.
docker/generated/Dockerfile.dotnet-8	Regenerated to include TypeScript LSP snippet.
docker/generated/Dockerfile.dotnet-9	Regenerated to include TypeScript LSP snippet.
docker/generated/Dockerfile.dotnet-10	Regenerated to include TypeScript + C# LSP snippets.
docker/generated/Dockerfile.golang	Regenerated to include TypeScript + Go LSP snippets.
docker/generated/Dockerfile.rust	Regenerated to include TypeScript + Rust LSP snippets.
docker/generated/Dockerfile.dotnet-playwright	Regenerated to include TypeScript + C# LSP snippets.
docker/generated/Dockerfile.dotnet-rust	Regenerated to include TypeScript + C# + Rust LSP snippets.
.github/copilot-instructions.md	Updates versioning instructions to reflect deriving CopilotHereVersion from VERSION and adds bump script guidance.