GA: additional mathematical material

Three small exact suites check the declared constructions with integers, sets, rational arithmetic, and \(\mathbb F_2\). The retained observable suite compares paired row-space closure with direct word enumeration, tests common-quotient and initialization criteria, and compares likelihood-profile updates with raw-world Bayes updates. It includes explicit switching, hidden-return, zero-probability, and memory-migration controls. The two retained suites are unchanged. The first-edition suite additionally checks quantized probability records, matched adaptive updates, block-error recurrences, and the joint sensor decision. These are bounded implementation checks, not universal proofs or agent experiments.