Couple particular devices and plans

[callumforrester]

inject gives us a mechanism to set default devices for plan parameters. As a user I want to not just set a default, but mandate a device so the user has no other option. The use cases are:

• Restricting the user from doing an untested operation
• Reducing the complexity of generated GUIs by removing the device parameter from the JSON schema

However, I recognise that flexibility and future proofing are a good thing, it is very easy to write a plan thinking it is a one-off and will only ever use a specific device, only to realise that it can be generalised, and it is generally better if that generalisation can be done by sending different parameter values rather than code changes. I think this is worth further discussion.

Tagging for interest, please forward as appropriate @GDYendell @douglaswinter @DiamondJoseph @olliesilvester @DominicOram

Acceptance Criteria

• It is possible to write plans with mandatory, rather than default devices
• These plans use the devices but make no reference to them in their parameter schemas

[DiamondJoseph]

I wonder if we could do something with inject(Literal["device"]) and reject any non-default param in that case?

[callumforrester]

Could also make a similar primitive to inject called require or similar