Naming of tables, fields and design unclear

It is time to get the messaging functionality into production as an added module looking at the future keycloak implementation.

Some questions and clarifications when looking at the attached ER.

1. It seems that "author.id" is used in "message.sender_id" as the reference. Why is there another reference since it is referenced through the content.author_id

2. Why is "bulk_message.author_handle" written out as handle(varchar) and not referenced as an id?

3. I am assuming that author will be populated or synced with treetracker.grower_account? This should be activated for all users right?

4. How does the stakeholder.stakeholder fit in here? Assumption: keycloak will manage admin panel users and stakeholder accounts which then allow admin panel users to send messages under the stakeholders names and details.

5. Is the messaging ER still up to date for the post domain migration v2 data structure?