PR_26171_GAMMA_010-replace-main-branch-guard-with-workstream-guard

[ToolboxAid]

Summary

• Replaces MAIN BRANCH EXECUTION GUARD with WORKSTREAM BRANCH EXECUTION GUARD.
• Removes the main-only BUILD start requirement.
• Allows execution from main or approved team/<TEAM>/<workstream> branches.
• Preserves hard stops for dirty repo, unapproved branch, TEAM mismatch, cross-team scope, detached HEAD, local/origin mismatch, and unpushed commits.
• Preserves GitHub authoritative workstream sync governance and owner-controlled EOD merge approval.

Validation

• git diff --check
• Targeted text check verifying old main-only hard stop is gone.
• Targeted text check verifying approved workstream branches are allowed.
• Targeted text check verifying local-only commits remain prohibited.
• Targeted text check verifying 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_010-replace-main-branch-guard-with-workstream-guard.md
• docs_build/dev/reports/PR_26171_GAMMA_010-replace-main-branch-guard-with-workstream-guard-manual-validation-notes.md
• docs_build/dev/reports/PR_26171_GAMMA_010-replace-main-branch-guard-with-workstream-guard-instruction-compliance-checklist.md

Merge Control

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