Expose the runtime catalog and carry an explicit runtime ID through workspace creation while preserving omitted-field compatibility for older clients.
The runtime POC made useGitActions require WorkspaceGitBoundary, but Command Center mounted that consumer without the boundary and crashed. Bind the active workspace at that consumer.
Keep provisional Worktree reservations unpublished until final placement so observers never bind the source checkout as the new workspace. Gate legacy cwd Git compatibility by hostVisiblePath instead of runtime kind because Local and Worktree remain host-visible runtimes.
Publish the rootless workspace runtime protocol, enforce module and host-execution boundaries, and prove an independently authored command runtime across lifecycle, PTY, files, Git, providers, and CI.
Establish the pipe-mode vertical slice before migrating terminals, files, Git, and providers. Runtime selection is immutable per workspace, and external runtimes remain unavailable to path-based daemon surfaces until those capabilities move behind the boundary.
Mohamed Boudra