Modify the notes capability model

[shawfactor]

From what i can determine notes are stored as WP_Comments with a comment_type of note, so all standard comments APIs work — you can query them with get_comments() or via the REST API. WordPress

However it appears the permission model is tied to the post_type in that users must have the edit_post capability for that post to create or view notes.

The core problem is that Notes are bolted onto the existing edit_post capability rather than getting their own capability axis. It conflates "can give feedback on content" with "can change content" — which are different roles in any real editorial or community workflow.
Almost every real-world use case wants to separate those, for example:

A club member who should be able to comment on a draft event page but not edit it
A client who reviews copy but doesn't touch it
A subject matter expert who annotates without authoring

The WP_Comments storage choice makes sense — it's the obvious place — but there should be a view_notes / create_notes capability pair independent of edit access.