Store which user triggered the creation of a snapshot by pressing the Node-RED deploy button.

### Description

We capture the user's ID when a user has created a snapshot via the FlowFuse interface but not when the snapshot is created due to a user pressing the Deploy button in Node-RED. For audit log purposes it would be useful to know who triggered the creation of a given snapshot.

### 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
```[tasklist]
### Tasks
- [ ] https://github.com/FlowFuse/flowfuse/issues/4529
- [ ] Capture who initiated auto-snapshot for a device
```