Instrument cleanup worker metrics

[haasonsaas]

Summary\n- add cleanup pass counters and duration histograms in the worker package\n- record cleanup stats on every successful worker pass\n- expose an optional worker endpoint via or \n\n## Testing\n- go test ./internal/worker ./cmd/asb-worker\n- go test ./internal/bootstrap ./cmd/asb-api ./internal/api/httpapi ./internal/app\n- go test ./...\n- git diff --check\n

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PR Summary

Medium Risk
Adds Prometheus instrumentation and an optional HTTP listener to the cleanup worker; low business-logic risk but introduces a new network surface and metrics registration behavior that could affect deployments if misconfigured.

Overview
Adds Prometheus instrumentation to the cleanup worker: a per-item-type *_cleanup_processed_total counter and *_cleanup_pass_seconds duration histogram, recorded after each successful cleanup pass.

Updates worker.Runner to accept a Metrics handle and record pass duration/stats, and extends asb-worker with an optional /metrics HTTP server (enabled via -metrics-addr / ASB_WORKER_METRICS_ADDR) with graceful shutdown. Tests now verify metrics are emitted for a cleanup run.

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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Three helper functions fully duplicated across packages

Low Severity

metricsPrefix, registerCounterVec, and registerHistogram are verbatim copies of the identical unexported functions already in internal/app/metrics.go. Any future bug fix to one copy risks being missed in the other. These could live in a shared internal package (e.g. internal/promutil) to eliminate the duplication.

Additional Locations (1)

• internal/worker/metrics.go#L108-L122

 

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