Launch the real Coordinator from VS Code

Parent

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

What to build

Make the VS Code Editor Adapter start the existing Four-Role Executable over stdio and establish a public LSP session in an Extension Development Host. Keep the adapter thin: it owns lifecycle and process launch while language semantics remain in the Coordinator and workers.

Acceptance criteria

• Opening a VS Code Extension Development Host activates the adapter.
• The adapter starts the real Coordinator over stdio rather than an in-process substitute.
• LSP initialization completes and the adapter reports server startup through its output/status surface.
• The adapter shuts down the Coordinator cleanly when the editor session ends.
• The default launch path is inferred from the repository build output and can be overridden.
• No editor-only semantic RPC layer is introduced.

Blocked by

• #11 — Build the VS Code adapter foundation

Start by reviewing the VS Code adapter foundation in blocked issue #11, then trace how the existing Four-Role Executable exposes the Coordinator over stdio. Validate the work in an Extension Development Host: activation should complete LSP initialization, report startup, infer or accept an overridden build path, and shut the Coordinator down cleanly.