Mandelbrot Viewer — runtime-cost removal build

Production source of truth is index.html.

This build starts from the integrated five-improvement viewer and applies the A/B-supported runtime-cost removals. The numerical architecture remains direct f32 / perturbation + series / sparse recovery / finite continuation / CPU fallback.

Validation

node tests/regression.mjs
node experiments/ab/variant_check.mjs index.html
node experiments/ab/supplement.mjs
node experiments/integrated_bench.mjs docs/removal-pass/integrated-bench.json

The optional real-browser WebGPU test is tests/browser_smoke.mjs; it requires Chromium with a working WebGPU backend.

Current records

• docs/removal-pass/IMPLEMENTATION.md — why each runtime cost was removed or retained
• docs/removal-pass/results.json — structural checks, hashes, and A/B evidence
• docs/removal-pass/integrated-bench.json — post-removal CPU/surrogate benchmark

Historical investigation records remain under docs/performance-cost-audit/ and docs/integrated-improvements/.