refactor: rename Recipient to Person, remove username, add userId FK

src/services/assignment.service.ts

@@ -81,7 +81,7 @@ export const AssignmentService = {
       },
     })
   },
-  findAllByRecipient: async (
+  findAllByPerson: async (
     recipientId: string,
   ): Promise<AssignmentWithRecipientItemAsset[]> => {
     return prisma.assignment.findMany({
@@ -143,4 +143,4 @@ export const AssignmentService = {
       data,
     })
   },
-}
+}