Distribute image archives through direct fabric

[FujitsuPolycom]

Result

Status: implemented, with GPU-free command and state-machine coverage. Direct-fabric throughput and live image import remain unqualified.

Add scripts/fanout_image_archive.py to download one checksum-bound image archive on a configured seed rank and forward it through the four-rank direct-link chain derived from the validated site topology. Management SSH starts and inspects work; rsync binds to each source fabric address and connects to the adjacent peer address.

The utility provides:

• plan-only default behavior;
• read-only --verify mode;
• explicit confirmation for execution;
• --create-only archive distribution without Docker import;
• bounded final and partial paths beneath an explicit target directory;
• exact-file reuse and conflict rejection without overwriting final files;
• resumable curl --continue-at - seed downloads;
• resumable rsync --partial --append-verify fabric hops;
• SHA-256 verification after every hop; and
• rank, hop, archive, topology, and optional image-import evidence.

No command from this branch was run against live hosts.

Validation

• python -m pytest scripts/test_fanout_image_archive.py scripts/test_sparkring_site.py -q: 141 passed
• ruff check --select E,F,W --ignore E501 scripts/fanout_image_archive.py scripts/test_fanout_image_archive.py: passed
• Offline planning against the sanitized GLM-5.3 TP4 site produced the expected 0→1→2→3 fabric chain and no remote operation.
• The broader python -m pytest scripts -q -rs run produced 508 passed and 3 skipped, plus one unrelated README assertion failure that reproduces unchanged on the stacked base.

This draft is stacked on #131 so its site/profile terminology matches that branch.

[FujitsuPolycom]

The resulting runtime, operator contract, and evidence are consolidated in retained draft stack #146 → #147 → #150. Independent page-base research remains in #149. Closing this superseded draft and deleting only its remote head branch.