Prompt to accept integration manager polices on use

[lampholder]

Before you:

• add a widget to a room
• allow a widget to load for you in a room
  • This does sort of work already with ToS for ISes/IMs: prompt on use screen matrix-org/matrix-react-sdk#3199, but the UX is such that your are prompted when entering a room with a widget, not when allowing it to display
  • Time of prompting for existing widgets fixed by Defer IM token until widget is shown and permission granted matrix-org/matrix-react-sdk#3240
• use the sticker picker

You must read and agree to the policy documents provided by the integration manager

[lampholder]

This will require a change to scalar (to expose a policy document) - will this also require a spec change?

[turt2live]

will this also require a spec change?

see #10087 (comment)

[lampholder]

We considered whether it would be possible for Scalar to handle this "internally" (i.e. scalar presents HTML that gets rendered in iframes in Riot, so why not just let it do this same trick to handle t's and c's acceptance) - however, by the time it rendered such an acceptance UX you would already have shared the mxid with the integration manager via OpenID, so this is not feasible.

[nadonomy]

After validating today, latest comps are in Zeplin: https://zpl.io/brMdWo3