Production incident: the orphan reap killed a legitimate SSH remote backend
started by another client machine. Its process sat at ppid 1 with the same
cmdline shape as a genuine orphan, and the exclusion list only covered THIS
app instance's children — ownership by OTHER clients was invisible.
The reap now treats every backend.lock.json under ~/.hermes/desktop-ssh/*/
as an ownership claim: lock payloads are schema-validated (mirroring
remote-lifecycle.ts) and their PIDs are excluded both before the scan and
re-checked after it (defense in depth against a lock written mid-scan).
Regression tests cover the exact incident shape: a lock-owned PID and a
genuine orphan with identical process shapes — only the orphan is reaped.
Also: fold the new single-field `runtime` config category into `agent`
(_CATEGORY_MERGE) and fix an env leak in the serve-startup test
(HERMES_SERVE_HEADLESS restored via monkeypatch) so the combined suites
run green in any order.