feature: Tasks tab added for lab organizations. tasks now can be assigned and their status can be updated by the assignee.

backend/prisma/schema.prisma

@@ -253,14 +253,21 @@ model LabCaseTask {
   stepOrder         Int
   stepLabel         String
   assigneeUserId    String?
+  assignedAt        DateTime?
+  priority          Int           @default(3)
   status            LabTaskStatus @default(PENDING)
 
   labCase  LabCase         @relation(fields: [labCaseId], references: [id], onDelete: Cascade)
   detail   TreatmentDetail @relation(fields: [treatmentDetailId], references: [id], onDelete: Cascade)
   assignee User?           @relation("LabCaseTaskAssignee", fields: [assigneeUserId], references: [id], onDelete: SetNull)
 
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+
   @@unique([labCaseId, tooth, treatmentType, stepOrder])
   @@index([labCaseId, status])
+  @@index([assigneeUserId, priority, createdAt])
+  @@index([assignedAt, labCaseId, priority])
   @@map("lab_case_tasks")
 }