Refactor models according to refined API spec

[Arlodotexe]

Fixes #3

Refactor models to align with the refined API spec.

• Project Model Changes:

  • Remove HeroImage, CreatedAt, and Icon properties.
  • Add ExtendedDescription property.
  • Remove constructor.
  • Provide default values for Images, Features, Dependencies, Collaborators, Links, and Connections.
  • Mark Publisher, Name, Description, Category, and CreatedAt as required.
  • Replace Cid with DagCid.
  • Change Collaborators to a Dictionary<DagCid, Role> type.
  • Use an empty collection expression [] instead of Array.Empty<T>.
  • Remove all JSON-related attributes.

• Publisher Model Changes:

  • Remove Owner, ContactEmail, and Icon properties.
  • Add Users + Roles, Connections, Links, ExtendedDescription, and ForgetMe properties.
  • Remove constructor.
  • Provide default values for Links, Projects, Users, ParentPublishers, and ChildPublishers.
  • Mark Name, Description, and Owner as required.
  • Replace Cid with DagCid.
  • Use an empty collection expression [] instead of Array.Empty<T>.
  • Remove all JSON-related attributes.

• User Model Changes:

  • Remove MarkdownAboutMe and Icon properties.
  • Add Projects + Roles, Publisher + Roles, and ExtendedDescription properties.
  • Rename MarkdownAboutMe to ExtendedDescription.
  • Provide default values for Connections, Links, Projects, and Publishers.
  • Mark Name and ExtendedDescription as required.
  • Replace Cid with DagCid.
  • Use an empty collection expression [] instead of Array.Empty<T>.
  • Remove all JSON-related attributes.

• Update Events Changes:

  • Update any mention of IsPrivate to IsUnlisted in ProjectUpdateEvent and PublisherUpdateEvent.
  • Remove lines 31 and 33 in ProjectUpdateEvent.

• Link Model Changes:

  • Replace Cid with DagCid.
  • Remove all JSON-related attributes.

• Role Model Changes:

  • Mark Name and Description as required.

• IModifiableEntity Changes:

  • Add UpdateExtendedDescriptionAsync method.
  • Add ExtendedDescriptionUpdated event.

• IReadOnlyEntity Changes:

  • Add ExtendedDescription property.
  • Add ExtendedDescriptionUpdated event.

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For more details, open the Copilot Workspace session.

[Arlodotexe]

This is largely done. Next steps will be to fix up the UpdateEvents (aligning with the new API surface) so we can compile again.

[Arlodotexe]

Latest changes fbf3eca should allow builds to pass. We can continue with refactoring UpdateEvents in another PR.

[Lamparter]

@Arlodotexe you might want to delete the branch 😁