Three more wins on top of the previous pass:
- sortQueueJobs memoizes the result for static sort keys
(filename, host, size) — these don't change during upload, so
every 200ms progress render now reuses the same sorted array
instead of running an O(n log n) Collator compare.
- _computeQueueStats caches within a single tick via queueMicrotask.
updateStatusBar + updateStatsPanel are always called back-to-back
and now share one queue scan instead of running two.
- _updateRowInPlace writes DOM values only when they actually
changed. Idle/queued/done rows (the majority) incur zero DOM
mutations per progress tick.
