P99 0 ms* autocomplete for 240M domain names

The Wirewiki autocomplete prefetches suggestions on keyDown and renders them on keyUp, achieving p99 latency of 0 ms, meaning 99% of results are ready before the key is released. It uses an in-memory trie for the top 1 million Tranco domains and an SSD-backed, memory-mapped block index for an additional 240 million CZDS domains, keeping most API responses under 2 ms and 99% of end-to-end requests under 15 ms at 1.6 k req/s.