Three robustness items off the future-work list:
1. Shipper sd_notify watchdog. Type=notify + WatchdogSec=180. The
daemon sends READY=1 after queue construction and WATCHDOG=1 once
per scan pass via a heartbeat callback wired into run_forever.
Restart=on-failure only catches process death — silent stalls
(deadlock, hung tar subprocess, blocked I/O past timeout) used to
leave a zombie running with the data backlog growing. Now systemd
kills + restarts the daemon if no WATCHDOG=1 arrives within 180s.
Verified end-to-end against systemd via `systemd-run --transient
--property=Type=notify --property=WatchdogSec=10`: unit transitions
to active on READY=1; SIGSTOP'ing the process triggers
`Watchdog timeout (limit 10s)! Killing process N with SIGABRT` at
exactly t+10s, then unit goes failed → restart cycle.
2. Quarantine cleanup. Without an upper bound, data/quarantine/ grew
forever as fatal episodes piled up. New ShipperConfig fields:
quarantine_keep_days = 30 # opt-out: 0 disables
quarantine_cleanup_interval_s = 3600 # gate so 5s tick doesn't
# statx() the whole tree
Cleanup runs at the start of run_once() but is gated to once per
hour. Removed entries logged.
3. Doctor surfaces shipping errors. Tails 10 minutes of cis490-shipper
journal and surfaces 412/400/transient patterns as red/yellow rows
with the canonical fix command. An on-device agent running
cis490_doctor.py now sees one line ("12 ship(s) rejected as
out-of-window") instead of needing to grep the journal.
Tests: 200/200 (was 188). New coverage: heartbeat callback fires +
survives exceptions; quarantine cleanup respects keep_days, gate, and
opt-out; doctor parser correctly classifies 412/400/transient/clean/
empty/journalctl-denied; both error classes prioritise 412 (more
actionable) when present together.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
