TE-003: UploadShellService documented UploadTransport as the swap seam, then
bound the concrete, unexported KeepaliveTransport class directly, so a spec
could not fake it. UPLOAD_TRANSPORT copies the SESSION_PORT shape; the
default factory returns the same instance, so runtime behaviour is
unchanged. upload-shell.service.ts goes from 0% to 88.57% line coverage
across 16 new specs for upload(), cancel(), delete() and pollReturning().
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
# Conflicts:
# docs/project/refactor-backlog-setup/refactor-backlog/99-backlog.md
# libs/shared/docs/behaviour-spec.mdx