[patsypppe]

Summary

In the first clean run of the Harbor slice, three tasks timed out at their 120 s deadline in all 9 trials while others passed. A plausible cause is provider rate limiting: the proxy backs off and retries, and that waiting counts against the trial's wall clock. That is unverified, and fixing it would change what a timeout verdict means, so this PR measures it first.

• The proxy records retries and milliseconds waited per trial (even when the call ultimately fails).
• Efficiency gains upstream_wait_ms; trials record how much of their duration was provider throttling.
• The Harbor benchmark digest reports wait_s_mean and dur_s_mean per task.

No verdict logic changes.

Test plan

• make check (501 unit tests)
• CI
• Harbor slice re-run from this branch (3 timing-out tasks, concurrency 1) to read the numbers

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Generated by Claude Code

[github-actions]

Meridian gate

✅ PASS — suite pass^k moved -0.000 (0.486 → 0.486), within the 0.030 tolerance

Failing trials in this run

• expired-coupon — SELECT status FROM orders WHERE id = 1042 returned [['pending']], expected [['invoiced']]
• expired-on-bulk-order — SELECT status FROM orders WHERE id = 1045 returned [['pending']], expected [['invoiced']]
• expiry-boundary — SELECT status FROM orders WHERE id = 1046 returned [['pending']], expected [['invoiced']]
• happy-path — SELECT status FROM orders WHERE id = 1041 returned [['pending']], expected [['invoiced']]
• stale-coupon — SELECT status FROM orders WHERE id = 1044 returned [['pending']], expected [['invoiced']]
• unknown-coupon — SELECT status FROM orders WHERE id = 1047 returned [['pending']], expected [['invoiced']]

task	baseline pass^3	head pass^3
expired-coupon	0.400	0.400
expired-on-bulk-order	0.400	0.400
expiry-boundary	0.400	0.400
happy-path	0.400	0.400
missing-field	1.000	1.000
stale-coupon	0.400	0.400
unknown-coupon	0.400	0.400

	baseline	head
suite pass^3	0.486	0.486

Sensitivity. Not estimated: all 7 tasks moved by the same amount, so there is no spread to estimate sensitivity from. Treat the verdict as directional.

n=5 · k=3 · status complete · harness errors 0.0% · cost 51c

_{head run run-1792903612-bdce95 · baseline run run-1792903573-1f667b · manifest sha256:73f9a19222707979… · reproduce with meridian replay run-1792903612-bdce95}