Ship keep-alive HTTP, 2 MiB single-buffer upload STOR, larger download
buffers, and live-validated Index All / FS transfer fixes. Add upload
performance docs and full feature test harness.
Match zftpd/ftpsrv single-buffer web upload (no large fallocate stall,
no TCP_NODELAY thrash, listen SO_RCVBUF 4 MiB). Harden Index All multi-root
with XDEV + visited set. Fix copy overwrite and free-space preflight.
Add ENABLE_ARCHIVE=0 slim build and goal_verify_io structural checks.
ItsBlurf