overview.json was missing a comma between the "Health Status" and
"App Error Rate (from logs)" panel objects, making the whole file
invalid JSON. Grafana's file provisioner skips dashboards that fail to
parse, so the entire "trails.cool Overview" dashboard (5 panels) never
loaded — a silent gap in observability. Validated with json.load.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>