Product MQTT payload schemas recommendations for Team Broker

### Description

We offer smart suggestions for payload structure for third-party brokers. This provides full UNS/MQTT schemas when a customer integrates in their third-party brokers to the FlowFuse UI (e.g. Hive MQ)

However, this is not supported for our in-built Team Broker, and this is leaving customers thinking that the payload schema generation work is broken.

### Related Epic:

https://github.com/FlowFuse/flowfuse/issues/4788

### Customers Impacted

- Raised by https://app-eu1.hubspot.com/contacts/26586079/record/0-2/10177258183

### Which customers would this be available to

Team + Enterprise Tiers (EE)

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate

Start by tracing the existing smart-suggestion and full UNS/MQTT schema generation flow for third-party brokers, then compare it with the Team Broker integration described here and in issue #4788. Done means Team Broker customers on the specified tiers receive the expected payload schemas without the UI suggesting that generation is broken.

Written by the indexing model from the issue text.