/reload-mcp -> shutdown_mcp_servers -> _kill_orphaned_mcp_children(include_active=True)
-> _send_signal -> killpg(pgid, SIGTERM). When a tracked MCP stdio child shares
the gateway's OWN process group, killpg delivers SIGTERM to the gateway itself,
firing its SIGTERM handler -> os._exit(0): /reload-mcp crashes the gateway.
Pre-compute the gateway's own pgid (os.getpgrp(), None on Windows/restricted)
and, in _send_signal, skip killpg when pgid == own pgid, falling through to the
per-pid os.kill path so the child is still reaped without self-signaling.
Adds a regression test (folded in) that pins the guard: with a tracked pgid
equal to the gateway's own pgid, killpg is never called for that pgid and the
per-pid kill fallback is used. Mutation-checked.
Co-authored-by: kshitijk4poor <82637225+kshitijk4poor@users.noreply.github.com>
23c47371d2