Resolve transcript -> summarize -> deliver, or skip when no usable
transcript. Sinks fail independently: a failing sink does not abort the
others and successful deliveries are kept; per-sink errors are returned
joined. Makes the two scaffolded acceptance scenarios GREEN.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Engine wires the ports and exposes ProcessNewVideo, the core use case. Returns
ErrNotImplemented on purpose so the acceptance suite fails RED — implementing it
to make those tests pass is the first build task. Depends only on ports + domain
(dependencies point inward).