Module select 

Deterministic selection and frontier ordering (PSP-10 Proposition 5, system 19).

No model confidence or vote appears in either rule. Every float comparison uses total_cmp; the final key is the unique branch id, so the order is total and the selection unique.

Structs

BranchCandidate

One eligible candidate offered to the selection rule.

FrontierEntry

One live frontier entry awaiting its quantum (system 19).

Functions

frontier_order

The deterministic epoch scheduling key (system 19’s six-key order). A heuristic for fairness — not an energy function, an acceptance rule, or a safety certificate.

select_branch

Proposition 5: hard pass, lower normalized energy, greater targeted improvement, lower recorded cost, lexicographically smaller branch id. Candidates whose sensor profile differs from the (unique) profile of the eligible set are excluded before comparison — a profile mismatch is never normalized after the fact.