feat(Circuits): cap entropy of overlapping actual features

[SamuelSchlesinger]

Samuel’s dot here.

Scope

Add a reusable finite-weight certificate for two Boolean features dominated pointwise by signed two-primary conjunctions with overlapping supports. The features may include arbitrary predicates of all primary inputs, including internal-gate dependencies.

The joint natural-log cost is J = 3 log 2 − (5/8) log 5, the entropy of (5/8, 1/8, 1/8, 1/8). The strict saving over two quarter-biased marginal caps is proved by the exact integer inequality 3^12 < 2^8 · 5^5. Equal supports, opposite signs, and constant false features are covered. This is a joint-cost cap, not a mutual-information lower bound.

The implementation uses the existing WeightBound infrastructure, an elementary pointwise-weight transport, and exact two-/three-bit tables. No PMF dependency is added. A matching blueprint node records the result.

This PR is the local pair-certificate layer. Assembly into a matched circuit-feature budget and the full inversion coefficient remain separate work.

Verification

The exact published source tree 70cb27fa854b73f02e701999e250d1ed52eed6ef passed:

• Full required aggregate build: Complexitylib, all five executable validation roots, seven ApiChecks modules, and runLinter (7,580 jobs)
• All six required environment-lint roots
• Style lint and all 25 maintenance-script tests
• Axiom guard: zero project axioms, standard axioms only
• Blueprint consistency: 1,233 nodes and 4,329 declaration links
• Additional API probes with an outside-support predicate and a constant feature

Independent review checked the statement, all overlap/sign cases, domination transport, and the unchanged pair patch after integrating dev be804d0. Fresh current-base CI passed every gate on integration commit ecbd7c4: https://github.com/SamuelSchlesinger/complexitylib/actions/runs/37262216960 .