AWS SNS node cannot publish to a phone number (SMS)

Bug Description The AWS SNS node's Publish operation always sends TopicArn to the SNS Publish API, so there is no way to publish a message directly to a phone number. The AWS SNS API supports this by passing PhoneNumber instead of TopicArn on the same Publish action: The node offers no PhoneNumber option and gives no hint that the direct SMS path is unsupported, so the only workarounds are to create a topic and subscribe the number to it (extra AWS setup, and a topic per recipient for anything dynamic), or to drop the node entirely and hand-sign the SNS request in an HTTP Request node. To Reproduce 1. Add an AWS SNS node to a workflow and select the Publish operation. 2. Look for a way to send the message to a phone number instead of a topic — the only available fields are Topic, Subject and Message. 3. To confirm the request that is sent, set any topic, execute the node, and inspect the outgoing request: it is /?Action=Publish&TopicArn=...&Subject=...&M…