Each has no way to observe cancellation, so a fan-out scanner (full
port sweep, directory brute-force) keeps draining its whole queue even
after ctrl-c or -max-time fires. EachCtx takes a context and stops
feeding workers once it's cancelled, while still handing the ctx to
the callback so an in-flight item can bail out too. Each is now a thin
wrapper over EachCtx with context.Background(), so existing callers
are unaffected until they opt in.
static i%threads stride partitions assign each item to a fixed worker, so a
goroutine stuck on a slow or timing-out host stalls while the rest idle behind
it (head-of-line blocking). add internal/pool.Each: workers all pull from one
shared channel, so a slow item only blocks its own worker and the others keep
draining. migrate git, ports, robots (scan), dnslist, dork, dirlist and
subdomaintakeover off the stride loops; per-item work, mutex-guarded appends and
progress increments are unchanged, results were already unordered.
