Expert: related resources and steps lost after website handoff when opening an instance

After starting a conversation on flowfuse.com/ai and continuing it via "Continue chat in FlowFuse", the conversation itself is preserved, but when the user then opens an instance, the conversation's related resources and steps are lost.

Intermittent; does not happen every time, so it needs reliable reproduction first.

- [ ] Reproduction documented and root cause identified.
- [ ] Related resources and steps persist after the handoff and instance navigation.
- [ ] Regression test added.

Estimate: ~3h diagnose + ~4h fix