0424 — The consumer inversion: consumption loops are worker rows the manager spawns

Context. The manager originally lived inside consumers, which made the consumer a special case: its consumption loops were private machinery rather than workers like everything else.

Decision. Ownership was inverted. The manager was lifted out of consumers, and the consumption loops (message_consumer, exception_consumer, delivery_consumer) became worker rows the manager spawns like any other worker. The public Consumer is a higher-order construct that seeds the rows and runs a manager runner; a bare ExceptionConsumer is a standalone retry loop with a self-claim door. Sub-consumers became pure factories, and queue/poolLimiter moved off constructor signatures.

Consequences. The consumer is not special, and the rest followed for free: the daemon is the same manager pointed at a different row, deployment scope is one WHERE clause, and suspending a consumption loop is the same target_instances toggle as any worker.