- Make ExtensionPointFactoryMiddleware an opaque type via new
@internal/backend package using OpaqueType from @internal/opaque
- Use options object for createExtensionPointFactoryMiddleware
- Make middleware function async (returns Promise<T>)
- Remove extensionPointFactoryMiddleware from createBackend, keep only
on createSpecializedBackend
- Export defaultServiceFactories from @backstage/backend-defaults
Signed-off-by: Jack Palmer <jackpalmer@spotify.com>