v2.16.0 - Wormhole qubit-coupling topology check (Experiment 14, honest negative result)

Tests whether the actual qubit-coupling topology of each instance's K=10 SYK quads -- which specific modes get coupled together, not just how many terms commute or how many terms touch a given mode -- predicts the sign-dependent instance variance.

A weighted 8-mode co-occurrence graph is built per instance (edge weight = how many quads couple that pair of modes). An ad hoc check before committing to this design caught a real methodology problem: a binary version of the graph (edge iff any co-occurrence) saturates to the complete graph K8 for most instances, useless as a discriminator -- the weighted count is used instead.

A second honest check, done after computing the real n=100 numbers: two of the four candidate features (max weighted degree, weighted degree std) turn out to be an exact linear rescaling of Experiment 11's mode-usage-count features (weighted degree = 3x usage count, verified to 1 part in 1e15) -- not new information. The two genuinely new features -- n_zero_pairs (how many of the 28 possible mode pairs are never coupled) and algebraic connectivity (the Fiedler value) -- also fail to correlate: r=+0.159 (p=0.114) and r=-0.141 (p=0.163).

A 6th and 7th candidate explanation ruled out, on top of Experiment 11's two, Experiment 12's structurally-trivial phase diagnostic, and Experiment 13's two. Seven independent hypotheses tested against the sign-dependent instance variance from Experiments 10/11; none hold up.

Full write-up: docs/wormhole_syk_teleportation.md#experiment-14-qubit-coupling-topology-check-run-2026-08-07