Module metrics 

In-process counters for the release-locks-at-submit feature.

PR1 uses AtomicU64 counters rather than pulling in a full metrics crate. The values are emitted through tracing::info! events with a standardized metric field so existing log-based tooling can aggregate them, and the counters themselves are readable from tests and any future Prometheus exporter we might bolt on.

Functions

incr_locks_released_on_submit

Increment the “locks released on submit” counter and emit a structured tracing event so log-based aggregators can surface it.

incr_stale_overlay_rejected

Increment the “STALE_OVERLAY rejected” counter.

locks_released_on_submit_total

Snapshot of the “locks released on submit” counter (for tests + future scrape endpoints).

stale_overlay_rejected_total

Snapshot of the “STALE_OVERLAY rejected” counter.