Core flows no longer reach into the terminal UI: build_source_package
takes a BuildSourceOptions struct (source tree, domain options, view,
prompter) and reports phases, messages and outcomes through the
environment-agnostic ports in the new report module. The classifiers
move from ui/logfmt to the core logfmt module, DebUi becomes a
BuildView adapter, the re-vendor retry asks the prompter instead of
checking for a TTY, and artifact/success printing moves to the CLI.
Headless consumers pass report::Quiet; an embedding (e.g. a builder
server forwarding events to a web frontend) implements BuildView and
maps the plain-data events onto its own wire format.
