posix.sh now implements the update-marker contract (C1/C2) as a lock:
- the daemon claims `.hermes-update-in-progress` as its first action with a v2
body (pid, started_at, `ct:` creation time) via an atomic no-replace create
(link(2)); a LIVE foreign owner refuses with exit 2 regardless of age, a
marker owned by --desktop-pid is adopted keeping its started_at, a dead one
is compare-and-deleted; liveness honours a line-4 `delegate:` (the running
`hermes update`), so an orphaned update is never reclaimed;
- the launcher waits for the daemon's claim and exits non-zero when it never
lands, so the Desktop does not quit into nothing;
- release is compare-and-delete and keeps a marker whose delegate is alive.
Outcomes follow C3: a legacy rebuild failure, a mac bundle stage/swap failure
or a relaunch gate after `hermes update` exited 0 is ok:true + warnings (no
more exit 6 / exit 7 "still on the previous version"). The result carries
started_at and warnings and is written via a per-pid tmp + rename.
Crash safety: start-of-run recovery restores an interrupted .app swap from its
aside copy (both swappers' suffixes) and a killed TCC heal backup, and sweeps
UI/probe litter of dead pids; the two swap renames are a signal-deferred
critical section. `hermes desktop`'s Python swappers recover the same state
instead of deleting the only copy first.
Also: probes are bounded (60 s), `hermes update` streams into the log, the
update child gets default TERM and the daemon default HUP (no SIG_IGN leak into
gateways or the relaunched app), the relaunched Linux app drops the update env,
the Desktop wait is zombie/pid-reuse aware and never relaunches over a live
app, serve-ui.py exits with its orchestrator, and the job section is parsed as
one brace group so `hermes update` rewriting posix.sh cannot shift the rest.
(cherry picked from commit c7dd9fab00b8af09321ec982d07a62f03351355d)
b54d069815