Added
- Prometheus metrics and
/healthzHTTP endpoint. New--metrics-port <PORT>flag (alsoKEI_METRICS_PORTenv var and[metrics] portTOML key) opts in to an HTTP server that exposes/metricsin Prometheus text format and/healthzas a JSON health snapshot matchinghealth.json. Metrics include cumulative counters (assets seen, downloaded, failed, per-reason skipped, bytes downloaded, bytes written, EXIF/state-write/enumeration failures, session expirations, interrupted cycles) and gauges (cycle duration, consecutive failures, last-success timestamp). When the flag is unset, no server starts and behavior is unchanged. (#225)
Full changelog: CHANGELOG.md