Add the local VsCodeProof acceptance target

Parent

#10 — Add cross-platform VS Code editor adapter for MrBuild LSP proof

What to build

Provide the complete local-only VsCodeProof flow that builds prerequisites, launches the isolated VS Code instance, and verifies the agreed editor-visible acceptance scenario across the real Coordinator and workers.

Acceptance criteria

• VsCodeProof is explicitly named for VS Code and is not part of the normal CI build chain.
• The target uses the shared fixture and disposable editor profile.
• The end-to-end flow proves diagnostics, hover, F# to C# navigation, C# to F# navigation, Workspace Status, and workspace reload.
• The flow supports both native executable and managed DLL launch modes.
• The flow exposes instance/profile/process information needed for editor-driven verification.
• Failures identify whether the build, adapter activation, Coordinator, worker, LSP request, or editor assertion failed.
• The existing stdio LSP harness remains green alongside the editor proof.

Blocked by

• #13 — Add the shared fixture and isolated VS Code proof launcher
• #14 — Prove editor diagnostics and hover
• #15 — Expose the Workspace Control Plane in VS Code
• #16 — Prove bidirectional cross-language source navigation
• #17 — Support managed DLL launch and debugger attach

Start by reading the shared fixture and isolated VS Code proof launcher from #13, then review the existing stdio LSP harness. Coordinate the blocked proofs in #14–#17 before assembling the local-only VsCodeProof flow. Done means the disposable editor verifies every listed scenario in both launch modes while failures identify the failing layer and the stdio harness remains green.