Added

• Publisher.DeclareQueueTopology(queueName, routingKey string) error - declares a durable queue, its binding to the configured exchange, and its dead-letter exchange/queue from the publisher side. The declaration is argument-identical to what a Consumer declares in Consume, so whichever side starts first, the other redeclares without a PRECONDITION_FAILED conflict. Declarations are idempotent.
• This closes a gap where messages published before any consumer had ever started were dropped by the broker as unroutable. Declaring the topology up front means those early publishes are buffered in the queue until a consumer attaches.