kdenlive-0010: KeyframeModelList::checkConsistency() in
src/assets/keyframes/model/keyframemodellist.cpp calls QList<GenTime>::contains()
inside nested loops — O(P*K^2) at clip load for multi-parameter keyframe effects.
Fix: std::set<GenTime> using operator< for O(log K) insert/lookup in both phases.
Speedup: 50x at K=100, 250x at K=500, 500x at K=1000 (P=3 params). 12/12 PASS.
Audacity: full 5-MOAD rescan on fresh clone confirms prior scan results.
No new defects. MOADs 0002/0003/0004/0005 CLEAN.
