Designing Google Docs-Like Permissions in Prisma?

I'm building an application that uses Prisma and need to design the database to have a Google Docs-like permissions architecture.

By "Google Docs-like" I mean that the application allows a user to have access to multiple "Projects", either by being the creator/author of those projects, or by another user giving them access to their created projects.

If as a user you have access to another user's projects, then you have a certain level of permissions granted to you by that user. This is where the application diverges from the Google Docs model. The three permissions levels are Editor, Reviewer and Viewer.

Here's part of my Prisma schema so far...

model User {
  id            String    @id @default(cuid())
  name          String?
  email         String?   @unique
  emailVerified DateTime?
  image         String?
  accounts      Account[]
  sessions      Session[]
  projects      Project[]
}

model Project {
  id        String   @id @default(cuid())
  name      String?
  things    Thing[]
  User      User     @relation(fields: [userId], references: [id])
  userId    String
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
}

What I can't figure out is the correct relation between User and Project to achieve either owning a Project, being a collaborator on a Project or a mix of both.

You can use explicit many-to-many relations to model this relationship:

model User {
  id            String    @id @default(cuid())
  name          String?
  email         String?   @unique
  emailVerified DateTime?
  image         String?
  accounts      Account[]
  sessions      Session[]
  userProjects  UserProject[]
}

model Project {
  id        String   @id @default(cuid())
  name      String?
  things    Thing[]
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
  userProjects UserProject[]
}

model UserProject {
  user   User   @relation(fields: [userId], references: [id])
  userId String
  project   Project   @relation(fields: [projectId], references: [id])
  projectId String
  role      Role
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  @@id([userId, projectId])
}

enum Role {
  EDITOR
  REVIEWER
  VIEWER
}

User and Project are connected through the UserProject model. This model represents the many-to-many relationship between users and projects. Each UserProject represents a user's relationship to a project. It includes a role field that can be EDITOR, REVIEWER, or VIEWER. This schema allows for a user to be the owner of a project, a collaborator on a project, or both.