An unclean desktop exit (crash / SIGKILL / update handoff) stranded every
`hermes serve` profile backend as an orphan (ppid=1) still serving, each
holding its MCP child subtree — 31 orphans / ~1.3 GiB RSS on one install.
Root causes + fixes:
- serve had no parent-death watchdog: add _start_parent_death_watchdog() in
web_server.py (mirrors slash_worker.py), gated on HERMES_PARENT_PID; os._exit
cascades to MCP watchdogs. No-op for standalone `hermes serve`.
- desktop passes HERMES_PARENT_PID in both serve spawn env blocks (main.ts).
- POSIX teardown now group-kills (process.kill(-pid, ...)) so MCP grandchildren
die too (backend-child.ts + waitForBackendExit SIGKILL fallback).
Windows path unchanged (forceKillProcessTree). Tests updated + passing.
XiaoZAZA
a9a0648f49