Checkpoint ring buffer ranked by improvement rate, plateau detection via liquid tau velocity, informed perturbation cycle (Adam reset, shrink-perturb, temp boost, LR×2), depth-limited rewind. ~150 lines in training_loop.rs, zero CUDA changes. Recovers from plateaus that prevention mechanisms (spread gradient, liquid tau) fail to avoid. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>