[AnthonyRonning]

Qualified Agent artifact downloads can fail before integrity verification on a valid slow connection: producer ZIPs had a 180-second deadline, while publication-stage ZIPs already allowed 900 seconds. The current 70.8 MB macOS artifact transfers at about 235 KiB/s and needs approximately five minutes. Three incomplete transfers were retained; none was extracted or accepted.

Use the same finite 900-second transfer budget for producer and stage downloads. Convert a subprocess timeout into a concise operator refusal while keeping the partial archive. There is no automatic retry or overwrite, and timeout failures produce neither extraction nor a success receipt.

Artifact size limits, exact IDs/ZIP digests, archive validation, source/provenance binding, independent attestations, signature verification, and protected publication approvals are unchanged. This changes the reusable operator only; it does not rebuild or change the already qualified Agent application packages.

Validation:

• 18 offline download-helper tests passed, including simulated 300-second success and over-900-second refusal with one request, preserved partial bytes, no extraction/receipt, and refusal to overwrite the partial file.
• Existing agent-updates lane passed, including publisher/Worker checks and a local deployment dry run.
• Existing repo lane passed all six root flake checks on macOS.
• git diff --check passed.

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