paskal / ralphex / 22034949020

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fix: use Setsid instead of Setpgid to prevent terminal signal hang

Previously, `Setpgid: true` created a new process group within the same
session, which meant the child inherited the controlling terminal. When
Claude CLI's descendants (zsh shell snapshot, gopls) attempted terminal
I/O, the kernel delivered SIGTTIN/SIGTTOU and stopped the entire process
group—hanging ralphex indefinitely.

After this change, `Setsid: true` creates a new session, fully
detaching the child from the controlling terminal. Process group
cleanup via `syscall.Kill(-pid, sig)` still works identically since
the child becomes session leader of its own process group.

Tested on macOS (Darwin 25.2.0, arm64) with Claude CLI v2.1.30–v2.1.42;
the hang reproduced 100% with Setpgid and 0% with Setsid.

1 of 1 new or added line in 1 file covered. (100.0%)

5230 of 6407 relevant lines covered (81.63%)

187.38 hits per line