feat: User services

prisma/models/organization-user-join.prisma

@@ -0,0 +1,14 @@
+model OrganizationUserJoinTable {
+  userId     String
+  orgId      String
+  role       ORG_ROLE @default(user)
+  joinedDate DateTime @default(now())
+
+  @@unique([userId, orgId])
+  @@map("organization_user_join")
+}
+
+enum ORG_ROLE {
+  admin
+  user
+}