D42 — cartographer disconnect: inverse of connect, inverse JSON merge, full provider prune

Decision. New subcommand cartographer disconnect [provider|all], business logic shared (doDisconnect) between CLI and TUI. Per provider: configurator.Remove (inverse of Apply) removes only the server's entry from the MCP config file without destroying the rest; provisioning.PruneManaged removes all the provider's managed files from the lockfile — not just the diff against the manifest — because disconnect must not depend on the server being reachable. Rationale. Reuse instead of duplication: PruneManaged/Remove are the same functions used by Apply, applied in the opposite direction. The "full" prune (the whole managed set) is the fundamental difference from sync: disconnecting is a local operation. Details: docs/configurator.md §cartographer disconnect.