R23-1/R23-2/R23-4：完成项目沟通回填与收口治理后端

server/prisma/schema.prisma

@@ -417,6 +417,22 @@ enum ProjectDeliveryRecordType {
   handover
 }
 
+enum ProjectCommunicationChannel {
+  wechat
+  phone
+  meeting
+  wecom
+  email
+  onsite
+  other
+}
+
+enum ProjectClosureChecklistStatus {
+  pending
+  done
+  waived
+}
+
 enum ConfidentialityLevel {
   public
   internal
@@ -564,6 +580,8 @@ model Employee {
   created_project_tasks            ProjectTask[]             @relation("ProjectTaskCreator")
   owned_project_risks              ProjectRisk[]             @relation("ProjectRiskOwner")
   owned_project_delivery_records   ProjectDeliveryRecord[]   @relation("ProjectDeliveryRecordOwner")
+  created_project_communication_logs ProjectCommunicationLog[] @relation("ProjectCommunicationLogCreator")
+  completed_project_closure_checklists ProjectClosureChecklistItem[] @relation("ProjectClosureChecklistItemCompleter")
   owned_contract_registries        ContractRegistry[]        @relation("ContractRegistryOwner")
   owned_confidential_document_refs ConfidentialDocumentRef[] @relation("ConfidentialDocumentRefOwner")
 
@@ -1767,10 +1785,12 @@ model Project {
   reimbursements  ReimbursementForm[]
   travel_requests TravelRequest[]
   todo_items      TodoItem[]
-  weekly_reports  ProjectLinkOnWeeklyReport[]
-  contracts       ContractRegistry[]
-  deliveries      ProjectDeliveryRecord[]
-  document_refs   ConfidentialDocumentRef[]
+  weekly_reports          ProjectLinkOnWeeklyReport[]
+  communication_logs      ProjectCommunicationLog[]
+  closure_checklist_items ProjectClosureChecklistItem[]
+  contracts               ContractRegistry[]
+  deliveries              ProjectDeliveryRecord[]
+  document_refs           ConfidentialDocumentRef[]
 
   @@index([owner_employee_id, status], map: "idx_projects_owner_status")
   @@index([manager_employee_id, status], map: "idx_projects_manager_status")
@@ -1880,6 +1900,53 @@ model ProjectLinkOnWeeklyReport {
   @@map("weekly_report_project_links")
 }
 
+model ProjectCommunicationLog {
+  id                    String                    @id @default(uuid()) @db.Uuid
+  project_id            String                    @db.Uuid
+  happened_at           DateTime
+  channel               ProjectCommunicationChannel
+  external_contact_name String?
+  external_org_name     String?
+  summary               String
+  next_action           String?
+  next_follow_up_date   DateTime?                 @db.Date
+  created_by            String                    @db.Uuid
+
+  created_at DateTime @default(now())
+  updated_at DateTime @default(now()) @updatedAt
+
+  project Project  @relation(fields: [project_id], references: [id], onDelete: Cascade)
+  creator Employee @relation("ProjectCommunicationLogCreator", fields: [created_by], references: [id], onDelete: Restrict)
+
+  @@index([project_id, happened_at], map: "idx_project_communication_logs_project_happened")
+  @@index([project_id, next_follow_up_date], map: "idx_project_communication_logs_followup")
+  @@index([created_by, created_at], map: "idx_project_communication_logs_creator_created")
+  @@map("project_communication_logs")
+}
+
+model ProjectClosureChecklistItem {
+  id           String                       @id @default(uuid()) @db.Uuid
+  project_id   String                       @db.Uuid
+  item_key     String                       @db.VarChar(64)
+  title        String
+  status       ProjectClosureChecklistStatus @default(pending)
+  note         String?
+  sort_order   Int                          @default(100)
+  completed_at DateTime?
+  completed_by String?                      @db.Uuid
+
+  created_at DateTime @default(now())
+  updated_at DateTime @default(now()) @updatedAt
+
+  project   Project   @relation(fields: [project_id], references: [id], onDelete: Cascade)
+  completer Employee? @relation("ProjectClosureChecklistItemCompleter", fields: [completed_by], references: [id], onDelete: SetNull)
+
+  @@unique([project_id, item_key], map: "project_closure_checklists_project_key_ux")
+  @@index([project_id, status, sort_order], map: "idx_project_closure_checklists_project_status")
+  @@index([completed_by, completed_at], map: "idx_project_closure_checklists_completed")
+  @@map("project_closure_checklist_items")
+}
+
 model ContractRegistry {
   id                    String               @id @default(uuid()) @db.Uuid
   contract_no           String               @unique