Two root causes for stale "active" incidents on the dashboard:
1. TypeError bug in _prune_stale_world: last_occurrence / resolved_at
can be an ISO-8601 string (stability-agent via events.py) or a Unix
int (node-agent). The previous session's auto-resolve did plain
`time.time() - last_occ` which raises TypeError for strings,
silently preventing _save_world() from being called and leaving
incidents perpetually "active" on disk.
Fix: add _parse_ts(ts) -> float that handles int, float, and
ISO-8601 strings uniformly. All timestamp arithmetic now goes through
it; returns 0.0 on None / garbage to keep comparisons safe.
2. Orphaned active incidents: _resolve_incident clears service["incident_id"]
and marks the incident "resolved" in memory, but if incidents.json was
truncated mid-write (pre-atomic-write era), the observer loaded it at
next startup with status="active" and no service entry pointing to it.
No code ever touched these orphans again.
Fix: _prune_stale_world now runs two cleanup passes each cycle:
- Case 1 (healthy-linked): service.status=="healthy" AND incident_id
still set → resolve immediately (service cannot have active incident)
- Case 2 (orphaned): active incident with no service link AND
last_occurrence > 5 min ago → resolve (5-min guard for creation race)
Both cases are wrapped in try/except so a bug here never crashes the
observer loop or blocks _save_world.
Also fixes the 7-day stale-incident prune to use _parse_ts so
ISO-string resolved_at values are handled correctly.
3. Operator UI: current_incidents() now filters to status=="active" only.
Resolved incidents were previously included in the /incidents endpoint,
making the dashboard show a wall of historical records as if active.
Nocturnal job investigation: _cleanup_control_plane_fs in node-agent runs
every 60s on VPS (not midnight-specific); it reads observer_checkpoint.json
(now written atomically) and deletes old event files. No non-atomic writes
found. Midnight clustering was likely external (logrotate / OS flush);
the supervisor's resilient loader already handles such transient issues.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
