status: seal high-dose Muon checkpoint 3126

[qcznlp]

Summary

• record remotely verified step-3126 backups for the active Muon 1e-3 and 3e-3 runs
• refresh the artifact-only 12-run handoff to 38/60 resumable checkpoints
• refresh the read-only W&B provenance audit at steps 3200/3140
• keep the paper-only publication scope explicit

Verification

• 16 focused tests passed
• all four updated/generated JSON artifacts parse
• portable evidence audit: 2,785 files, 107,442,256 bytes
• paper layout: main text ends on page 8
• git diff --check