Constant POOL_RECHECK_INTERVAL 

pub const POOL_RECHECK_INTERVAL: Duration;

Wall-clock cadence for the serve loops’ mid-stream pool-solvency re-check (ADR 003 §Pool solvency policy).

The re-check re-reads this projection to catch a pool other lanes drain remaining down on mid-stream. Two facts make a wall-clock cadence — not a per-voucher-boundary one — the right frequency:

• The projection only advances as the settlement watcher folds PoolRedeemed logs (roughly the event-poll cadence), so re-reading it faster than that returns the same value — wasted work on exactly the fast streams that cross voucher boundaries most often.
• Per-stream throughput is bounded (credit window + voucher pacing), so a wall-clock interval T bounds worst-case over-delivery on a drained pool to T × per-stream-rate — an explicit, bounded exposure. The on-chain redeem (min(desired, remaining), partial-on-drain) remains the backstop.

At ~2 s a ~1 Gbps stream over-delivers at most ~250 MB before it stops — sub-percent of a multi-GB blob, the core large-file workload.