Pin the reviewed Bun fork with the corrected WebKit string bounds checks, remove the CSS tokenizer workaround, and reduce native worker, fallback, browser and fixture overhead while preserving all assertions and Node GC coverage.
The complete matched Linux comparison preserves 1,494 files, 25,127 passing cases and four skips. Bun reduces summed shard command time by 3.60% and the slowest shard by 1.18%. The unsharded run passes within the unchanged 10 GiB sampled-PSS guard. Full release verification retains both runtimes.