PR_26171_GAMMA_009-github-authoritative-workstream-sync

[ToolboxAid]

Summary

• Adds GitHub Authoritative Workstream governance to PROJECT_INSTRUCTIONS.md and PROJECT_MULTI_PC.txt.
• States GitHub is the authoritative workstream record.
• Prohibits local-only commits and requires completed PR scopes to be committed and pushed before continuing.
• Adds start-gate sync validation for clean branch, local == origin, detached HEAD, unpushed commits, push failure, and ownership mismatch.
• Preserves owner-controlled EOD merge approval.

Validation

• git diff --check
• Targeted text checks for GitHub is the authoritative workstream record.
• Targeted text checks for local-only commit prohibition.
• Targeted text checks for branch-ahead-of-origin hard stop.
• Targeted text checks for EOD merge approval enforcement.

Skipped by request:

• Playwright, because this is docs/static governance work only.
• Samples smoke, because this is docs/static governance work only.

Reports

• docs_build/dev/reports/codex_review.diff
• docs_build/dev/reports/codex_changed_files.txt
• docs_build/dev/reports/PR_26171_GAMMA_009-github-authoritative-workstream-sync.md
• docs_build/dev/reports/PR_26171_GAMMA_009-github-authoritative-workstream-sync-manual-validation-notes.md
• docs_build/dev/reports/PR_26171_GAMMA_009-github-authoritative-workstream-sync-instruction-compliance-checklist.md

Merge Control

Draft PR only. Not merged. EOD merge remains owner-controlled and requires explicit approval.

[ToolboxAid]

Closed by Governance Phase 1 completion and historical consolidation.