RegisterMcpStep built the registration URL from ctx.ExternalMcpPort, which the
Update pipeline never repopulates from the existing installation, so any
update silently re-registered the wizard default (47822) even when
worker.config.json had a different port configured. InstallerWorkerConfig was
also missing external_mcp_port entirely, so the installer had no way to read
it back. Port 0 (external listener disabled) now skips registration instead
of pointing Claude at 127.0.0.1:0/mcp.
mika kuns
3462ca1355