`_reap_unsupervised_gateway_orphans()` short-circuits on Linux hosts
with systemd via `supports_systemd_services()`, but returns `False` on
macOS — there is no systemd. This means the orphan reaper runs
unconditionally on macOS and treats the launchd-managed gateway as an
unsupervised orphan, SIGTERM-ing it.
When Hermes Desktop opens, `hermes serve` calls this function during
startup (web_server.py line ~251, gated on `HERMES_DESKTOP == "1"`).
The launchd gateway is killed, launchd restarts it via `KeepAlive: true`,
and the user sees a spurious gateway restart every time they reopen the
Desktop app.
Fix: exclude PIDs managed by launchd (`_get_service_pids()` already
returns launchd-managed PIDs on macOS) from the orphan scan, the same
way systemd PIDs are excluded on Linux.
Tested on macOS 26.5 (Tahoe) with Hermes Desktop 0.16+ and a
launchd-managed gateway (`ai.hermes.gateway` plist with `KeepAlive`).
Before the fix, quitting and reopening Hermes Desktop restarted the
gateway every time. After the fix, the gateway stays running across
Desktop quit/reopen cycles.
ce20857f5a