The slot wait was a fixed 5 minutes from the moment a file started queueing. With 46 fixture files sharing 2 slots the queue outlasted that, so whichever file came last failed the gate at random (runs 1742 and 1746). The deadline now restarts whenever a slot changes hands; only 10 minutes with no slot changing hands (a hung holder) fails. The 2-slot cap from BUG-281 stays. Full suite 4967 / fail 24, identical to 171a3f25; tsc 0; lint 0 errors. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017eEAG8HD3mm8gsKXgk8uU8