ProcessReader.Follow(owner, state, tool, stream) takes the owner's read tool and its views stream as the owner's
declaration names them, and refuses another owner's tool or a second stream for one owner; OwnerReadTool, StreamOf,
IndexerStream and AssignerStream are gone, and viewstest takes the same two values. The second instance of a module
name in shared code (the earlier review finding), so the package test now refuses a module's name in go/views.
Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig