T3 approval is process-wide state (not safe for concurrent or embedded use) #28

Status: Verified during the Pick Your AI rollout (reproduced, or read directly in the code).

Part of epic: Epic: Make co-owner (T3) sign-off auditable and safe.

Summary

PR #20 stores the approval in a module-level flag and restores it when main() returns. That fixes the leak between invocations but is still unsafe if two calls run concurrently in one process.

Evidence

• config.set_t3_signed_off writes a module global read by check_owner, art_status, footer_status, doctor, topics and org planning.
• An independent code review flagged threads/async embedding as unsafe. Not reproduced with a concurrent test (none exists).

Impact

A library embedder running a signed-off and an unsigned call concurrently could let the unsigned one through.

Proposed fix

Carry approval in a contextvars.ContextVar (or pass it explicitly through RepoContext).

Acceptance criteria

• Two threads, one signed off and one not, behave independently.
• No module-level mutable approval state remains.

Tasks

Each task below is a sub-issue.

Prior work

Prior work: open PR #20 (opt-in --allow-t3 and the Pick Your AI family), open #7 and PR #13 (variant J badges), merged PRs #14 to #19 (icon art-direction path, UTF-8 output, registry-free org health and label planning, Windows test portability, footer URL repair) and closed issues #8 to #12. Nothing here duplicates those; where an item is already handled it is linked, not refiled.

Fresh VM verification: not run. Findings were verified on a Windows host; hosted CI is separate evidence.