Declares the Prometheus metrics that shigoto_metrics_handlers updates from shigoto telemetry events.

High-cardinality keys (job_id, batch_id) deliberately stay out of metric labels; they remain on the raw telemetry events for tracing or audit sinks that need them. Labels are limited to bounded dimensions: worker, queue, priority, snooze reason, cron name, and testing mode.

Label values MUST be bounded, developer-controlled dimensions. Never route untrusted input into a queue name, a priority, or a snooze reason (e.g. a worker snoozing with a per-job id embedded in the reason): each distinct value mints a new Prometheus series and unbounded values are a cardinality DoS on both the exporter and the scraping Prometheus.

The [shigoto, job, progress] event is intentionally NOT exported. It is a per-job 0..100 percentage that only aggregates meaningfully keyed by job_id, which is excluded on purpose; it has no bounded counter or histogram shape.