[Upstream] Review xai-org/grok-build changes

[github-actions]

A newer state of xai-org/grok-build is available for review.

• Last reviewed commit: 07b2f714
• Current upstream commit: 72a61251fcffb464bcc687aeb5a998e5a98ec0c9
• Last reviewed upstream version: 1.0.8
• Current upstream version: 1.0.16
• Last reviewed release: none
• Current upstream release: none

Review and port relevant changes according to the upstream sync procedure. Do not merge upstream wholesale or update .github/upstream.json before the selected changes pass the Chutes Build quality gates.

[TheStreamCode]

Upstream watch review - 2026-08-30

Checked against baseline 07b2f714 (1.0.8, reviewed 2026-08-25):

• Upstream has moved to 1.0.12 (bc7f02ed, 2026-08-28) across 4 squashed commits.
• Delta: 1578 files, +123,986 / -78,379. This is a multi-release delta (1.0.8 -> 1.0.12), not an incremental one.
• Recommended starting point: python scripts/port_assist.py --base 07b2f714 to classify clean-take vs mechanical vs judgement, then port one area per commit per docs/upstream-sync.md.

No action taken in this pass - the delta warrants its own porting session. Baseline in .github/upstream.json remains 07b2f714 / 1.0.8 until the port lands.