db-core-mutations-optimistic

collection.insert, collection.update (Immer-style draft proxy), collection.delete. createOptimisticAction (onMutate + mutationFn). createPacedMutations with debounceStrategy, throttleStrategy, queueStrategy. createTransaction, getActiveTransaction, ambient transaction context. Transaction lifecycle (pending/persisting/completed/failed). Mutation merging. onInsert/onUpdate/onDelete handlers. PendingMutation type. Transaction.isPersisted.