Simplify GPU compute by reverting to vec2 and implementing G function since performan...

Simplify GPU compute by reverting to vec2 and implementing G function since performance difference is almost nonexistent and the real benefit comes from native u64 types which do not yet exist in WGSL. Increase workgroup size to best value 96 found during testing on RTX 3070. Create --benchmark CLI argument. Store seed and blockhash in fast shared workgroup memory. Add benchmark convenience npm script. Fix documentation in inline help and manual page. Fix CLI default port collision with server default port. Change timestamp on server log files. Test concurrent curl requests to server. Fix action listed in server response error message. Update puppeteer and test page HTML with blank favicon to prevent unnecessary load.