mf.proto named git.eeqj.de/sneak/mfer/mfer as its Go package, which
disagrees with the sneak.berlin/go/mfer module path go.mod declares.
go_package is now sneak.berlin/go/mfer/mfer, the import path of the
mfer/ package. mf.pb.go is regenerated with make generate, which
changes only the go_package bytes in its embedded descriptor, and
mf.proto.sha256 records the new mf.proto hash.
Model: opus-5-5