VMAF model, pooling, and confidence-interval analyzer

A dependency-light Python script (standard library only) that reads a libvmaf JSON log — with or without the bootstrap confidence-interval fields — and reports the score pooled four ways (mean, harmonic mean, 5th percentile, single worst frame), prints the 95% confidence interval when a bootstrap model was used (both the percentile [ci95_low, ci95_high] and the score ± 1.96·stddev normal forms), and, given two logs, returns a significance verdict for the gap read against both the overlapping err