v2.4.1

Fixed

• Calibration decision tree — severe delivery-timing failures (failed releases, p99 > 15 ms, late > 10 ms count > 5) now route to audience_safe; local_precise is reserved for infeasible same-key repeats without timing failure. Missed-note failure modes no longer pick the tightest profile.
• Tempo scaling — rec_tempo is now min(current, target) in both severe and moderate branches, so a user tempo of 0.93 on a 0.95 target no longer rounds upward to 0.95.
• Excellent-timing path — keeps the user's current profile instead of always recommending local_precise; the calibration report now confirms rather than changes.
• Latency margin guard — calibrated margin recommendation is rejected when sample count n < 50, preventing low-sample p99/p50 quantiles from poisoning the input-latency guard.

Changed

• docs/timing-profile-frame-model.md: updated severe-failure routing description to match the new audience_safe vs local_precise split.

Notes

Shader-free pure-scheduler patch. No SendInput, platform, or updater surfaces touched. Build provenance attested.