Bypass Palette Manger for installation or update

**Parent Deliverable:** FlowFuse/product#47 — Expert as Agentic Co-pilot

### Description

In https://github.com/FlowFuse/flowfuse/issues/6605 we intrduced "Update Avaiable" and in prior works we added the ability to install contrib nodes from the Expert Output. These both take the user to the Palette Manager.

Ideally, they would operate the action that the palette manager takes however the necessary logic checks and preparation is performed in the palette manager (on the click handler)

This task is to explore if it is possible / desirable to side-step the palette manager

Considerations
- include visual feedback of installation process
- interlock/anti-repeat of chat button

This task will likely need breaking down into at least 3 sub tasks:
- FF Side
- Node-RED core work
- Changelog

### Epic/Story

_No response_

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

I have provided an initial effort estimate