Details

When running remote MCP servers via the CLI, the --proxy-port flag works correctly. However, when using the registry configuration, the proxy_port field is not part of the RemoteServerMetadata schema and is ignored for remote servers.

ImageMetadata has proxy_port (toolhive-core registry/types/registry_types.go), but RemoteServerMetadata does not. The config builder in pkg/runner/config_builder.go only reads proxy port from ImageMetadata, so registry-defined remote servers can never pin a proxy port.

Changes needed

1. toolhive-core: Add ProxyPort int field to RemoteServerMetadata in registry/types/registry_types.go
2. toolhive: Update pkg/runner/config_builder.go to read ProxyPort from RemoteServerMetadata when imageMetadata is nil
3. Update the publisher-provided and legacy registry JSON schemas to allow proxy_port on remote server entries