- Precompute edit_vec = (strength * sign) * dc_removed_pc1_dir once in
closure instead of recomputing pc1_dir mean removal every denoising step
- Remove SharpnessData.pc1_std (stored but never used since dropping
pc1_std multiplier)
- Blur single-channel gray noise, expand to 3-channel per-batch instead
of allocating full 201 MB 3-channel copy upfront
- Remove unused LCSData import