Commit 2025-12-28 17:51 542e047a

feat(Algebra): stably finite rings (#32262)

• Show finite semirings are stably-finite.
• Show stable finiteness is left-right symmetric.
• Prove matrix characterizations of rank condition and invariant basis number; as consequences, show both properties are left-right symmetric.
• Show stable finiteness implies the rank condition, generalizing rankCondition_of_nontrivial_of_commSemiring.
• Reformulate a lemma as saying division rings are stably finite.