AppD consolidated update PR

[kriswest]

Consolidated PR for AppD updates (each of which is raised as a separate PR into this branch for review by AppD discussion group members, maintainers and editors).

resolves #369
resolves #370
resolves #553
resolves #555
resolves #556
resolves #558
resolves #560
resolves #561
resolves #562
resolves #565
resolves #566
resolves #567
resolves #622

[robmoffat]

Good job - read this pretty closely didn't notice any typos / errors.

I've approved but I have this one note:

I notice this page hasn't received any changes: https://deploy-preview-668--lambent-kulfi-cf51a7.netlify.app/docs/next/app-directory/discovery

I was reading this through again, and to my (untrained, noob) eye the part about "Application ID namespace syntax host resolution" really stands out as not relevant now. If we're moving to the model we talked about on Monday of "get all the appD records from all the app directories" then I don't see what use this naming scheme is.

The only use-case I can see is one app wanting to load another.. but if that was happening, I don't think the app would know anything about the app directory, would it?

[mattjamieson]

LGTM!

[kriswest]

@greyseer256 changes applied

[kriswest]

@robmoffat apologies, thought I'd replied to the below:

I notice this page hasn't received any changes: https://deploy-preview-668--lambent-kulfi-cf51a7.netlify.app/docs/next/app-directory/discovery

I was reading this through again, and to my (untrained, noob) eye the part about "Application ID namespace syntax host resolution" really stands out as not relevant now. If we're moving to the model we talked about on Monday of "get all the appD records from all the app directories" then I don't see what use this naming scheme is.

The only use-case I can see is one app wanting to load another.. but if that was happening, I don't think the app would know anything about the app directory, would it?

The discovery page got merged into the overview in the formal spec re-org and shuffled around a little so that the manual config of appD was promoted to first in the list (as the primary way appDs are discovered IRL). The group hasn't discussed discovery as yet but can look at it in future. Its worth noting that the main use-case for fully qualified appIds is making them globally unique, rather than discovery. However, I think it will remain useful to be able to track back to the appD from the fully-qualified Id - perhaps more so once Desktop Agent Bridging arrives and you start seeing comms between apps on different desktop agents, which may not know about the same appDs as each other...