Use inline senders on the tenanted Azure Service Bus path (GH-3826)

[jeremydmiller]

Closes #3826.

Not a routing bug

The issue reported a message published without a tenant id being Sent and never Received, and concluded it was "real multi-tenant conventional-routing behaviour". The route was correct and the listener was Accepting the whole time — the send failed.

TenantedSender deliberately does not implement ISenderRequiresCallback, so that SendingAgent picks sendWithExplicitHandlingAsync for the fire-and-forget senders beneath it (GH-2361). But EndpointCollection.CreateSendingAgent only calls RegisterCallback when the top-level sender implements that interface, and it does not recurse:

if (sender is ISenderRequiresCallback senderRequiringCallback && agent is ISenderCallback callbackAgent)
{
    senderRequiringCallback.RegisterCallback(callbackAgent);
}

Azure Service Bus put a BatchedSender under the TenantedSender, so _callback stayed null and every batch threw:

System.InvalidOperationException: This sender has not been registered.
   at Wolverine.Transports.Sending.BatchedSender.SendBatchAsync(...) BatchedSender.cs:line 124

So a tenanted ASB endpoint could not send anything — tenanted or untenanted.

The fix follows existing precedent

Redis, MQTT and Pub/Sub each already hit this and worked around it the same way, every one with a comment naming GH-2361 — e.g. RedisStreamEndpoint:

Both the tenant senders and the default fallback MUST be the fire-and-forget InlineRedisStreamSender — TenantedSender does not forward RegisterCallback, so a BatchedSender under it would silently drop every message (GH-2361).

ASB was simply never given the same treatment. This does that, rather than rework the callback plumbing across four transports. InlineAzureServiceBusSender awaits the real broker send, so the outbox marks success only after the broker has the message.

Also: a test bug worth 2 minutes

The test set the tenant's ManagementConnectionString to the AMQP endpoint (5673) instead of the management endpoint (5300), so every tenant provisioning call hung to its own timeout. That is where the issue's 4m28s came from. Class drops 5m33s → 2m29s.

Verification

• Red baseline confirmed: both new tests fail without the product change, pass with it.
• Bug_1933 2/2, untagged from Category=Flaky.
• New tenanted_senders_are_inline_3826 asserts the sender shape and that an untenanted publish round-trips.
• Full ASB suite 315/315 green.

🤖 Generated with Claude Code

https://claude.ai/code/session_01WHAuhdWS3XeAk16swV9G8m