New calibration (core/sharpness.py) generates blur stimuli, VAE-encodes, and extracts PC1 as the sharpness direction. New nodes (nodes/sharpen.py) provide LCSSharpnessCalibrate (auto-cached per-VAE) and LCSSharpnessIntervene (post-CFG hook with strength, step window, mask). Positive strength = sharper, negative = blurrier.