SurfacePairing

Mode pairing from q., and the span that is the whole of its advantage

5/5 passed in 0ms

Test	What it does	Result
test_drift_shape	The drift shape reads pairing_drift instead, reporting a mean phase excursion and a larger e_x, and the yield shape reports no excursion at all.	✅ pass
test_pairing_decoy	The pair intensity ladder has six ascending rungs summing to one where a round carries three intensities, and the four basis labels sum to one, both slots empty at the vacuum draw squared.	✅ pass
test_pairing_route	The route is the rate Zeng's five engine calls compose by hand, bit for bit, with the phase error from Ma and Razavi through mdi_yield.	✅ pass
test_span_buys	The rate rises with the pairing interval, a span of ${10}^4$ buying more than 25 times a span of one round.	✅ pass
test_window_span	q.rates.window("pairing", ...) is pairing_span: 3125 rounds at 625 MHz and 5 us, and a reference not surviving one round is refused.	✅ pass