Register an org-level public GitHub skill source and numeric repository identity. An omitted migration-compatible identity leaves the row visible but non-installable until bound: projection omits it from AgentSpec. The daemon acquires a bounded local snapshot; the remote source is never passed to the CLI. skills empty ⇒ install every skill the snapshot exposes. Rejected with 409 while any agent already enables skills under the requested source name — agents bind by name, so a new source must not silently capture existing selections.