improvement: tasks and cases feature updated based on the new prosthesis types and their steps. the whole assignment proccess removed from the flow.

backend/prisma/schema.prisma

@@ -23,7 +23,9 @@ model User {
   sessions           Session[] // 👈 ADD THIS - opposite relation for Session
   sentStaffInvites   StaffInvitation[]
   sentOrganizationInvitations OrganizationInvitation[]
-  assignedLabCaseTasks LabCaseTask[] @relation("LabCaseTaskAssignee")
+  statusChangedLabCaseTasks LabCaseTask[] @relation("LabCaseTaskLastStatusChangedBy")
+  labCaseTaskStatusEvents LabCaseTaskStatusEvent[]
+  labCaseComments LabCaseComment[]
 
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt
@@ -65,6 +67,7 @@ model Organization {
   appointments     Appointment[]
   treatments       Treatment[]
   labCaseSends     LabCaseSend[]
+  labCaseComments  LabCaseComment[]
 
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt
@@ -115,11 +118,15 @@ model Appointment {
 }
 
 enum LabTaskStatus {
-  PENDING
   IN_PROGRESS
   COMPLETED
 }
 
+enum LabCaseCommentSide {
+  LAB
+  CLINIC
+}
+
 model Treatment {
   id             String   @id @default(uuid())
   organizationId String
@@ -194,6 +201,7 @@ model LabCase {
   sends           LabCaseSend[]
   tasks           LabCaseTask[]
   toothProsthesis LabCaseToothProsthesis[]
+  comments        LabCaseComment[]
 
   @@index([treatmentId, sortOrder])
   @@map("lab_cases")
@@ -306,31 +314,66 @@ model LabCaseTask {
   id                 String        @id @default(uuid())
   labCaseId          String
   treatmentDetailId  String
-  tooth              String
+  teeth              Json
   treatmentType      String
   prosthesisTypeCode String
   workflowStepCode   String
   stepOrder          Int
   stepLabel          String
-  assigneeUserId     String?
-  assignedAt         DateTime?
-  priority           Int           @default(3)
-  status             LabTaskStatus @default(PENDING)
+  isImportant        Boolean       @default(false)
+  status             LabTaskStatus @default(IN_PROGRESS)
+  lastStatusChangedByUserId String?
+  lastStatusChangedAt       DateTime?
 
   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)
+  lastStatusChangedBy User? @relation("LabCaseTaskLastStatusChangedBy", fields: [lastStatusChangedByUserId], references: [id], onDelete: SetNull)
+  statusEvents LabCaseTaskStatusEvent[]
 
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt
 
-  @@unique([labCaseId, treatmentDetailId, tooth, stepOrder])
+  @@unique([labCaseId, treatmentDetailId, prosthesisTypeCode, stepOrder])
   @@index([labCaseId, status])
-  @@index([assigneeUserId, priority, createdAt])
-  @@index([assignedAt, labCaseId, priority])
+  @@index([labCaseId, isImportant])
   @@map("lab_case_tasks")
 }
 
+model LabCaseTaskStatusEvent {
+  id         String        @id @default(uuid())
+  taskId     String
+  fromStatus LabTaskStatus?
+  toStatus   LabTaskStatus
+  changedByUserId String?
+  changedAt  DateTime      @default(now())
+
+  task LabCaseTask @relation(fields: [taskId], references: [id], onDelete: Cascade)
+  changedBy User?  @relation(fields: [changedByUserId], references: [id], onDelete: SetNull)
+
+  @@index([taskId, changedAt])
+  @@map("lab_case_task_status_events")
+}
+
+model LabCaseComment {
+  id                   String             @id @default(uuid())
+  labCaseId            String
+  authorUserId         String?
+  authorOrganizationId String?
+  authorSide           LabCaseCommentSide
+  body                 String
+  visibleToClinic      Boolean            @default(false)
+
+  labCase      LabCase       @relation(fields: [labCaseId], references: [id], onDelete: Cascade)
+  authorUser   User?         @relation(fields: [authorUserId], references: [id], onDelete: SetNull)
+  authorOrganization Organization? @relation(fields: [authorOrganizationId], references: [id], onDelete: SetNull)
+
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+
+  @@index([labCaseId, createdAt])
+  @@map("lab_case_comments")
+}
+
 model Plan {
   id       String @id @default(uuid())
   name     String @unique // "Solo", "Small", "Medium", "Large", "Enterprise"