ArtifactType, the single enum naming the artifact sources the
CLI operates over, plus ArtifactRef — an artifact’s identity
and stat-level fingerprint — and the stamp helpers that produce
those fingerprints for sync and import provenance.
path resume <input> — fetch / load a Toolpath document, pick an
installed coding-agent harness, project the session into that
harness’s on-disk layout, and exec the harness’s resume command.
The harness layer over ArtifactType: Harness names the
agent runtimes sessions can be shared from and resumed into, and
HarnessBundle carries one provider manager per installed harness
for commands that aggregate across them.