BIZ8-11 增强采购项目关联

server/prisma/schema.prisma

@@ -1047,6 +1047,7 @@ model PurchaseRequest {
   supplier_id            String?               @db.Uuid
   document_category_id   String?               @db.Uuid
   budget_pool_id         String?               @db.Uuid
+  project_id             String?               @db.Uuid
   title                  String                @default("")
   reason                 String?
   currency_code          String                @default("CNY") @db.VarChar(8)
@@ -1067,6 +1068,7 @@ model PurchaseRequest {
   supplier          Supplier?         @relation(fields: [supplier_id], references: [id], onDelete: SetNull)
   document_category DocumentCategory? @relation(fields: [document_category_id], references: [id], onDelete: SetNull)
   budget_pool       BudgetPool?       @relation(fields: [budget_pool_id], references: [id], onDelete: SetNull)
+  project           Project?          @relation(fields: [project_id], references: [id], onDelete: SetNull)
 
   items              PurchaseRequestItem[]
   attachments        PurchaseAttachment[]
@@ -1082,6 +1084,7 @@ model PurchaseRequest {
   @@index([supplier_id], map: "idx_purchase_requests_supplier")
   @@index([document_category_id], map: "idx_purchase_requests_document_category")
   @@index([budget_pool_id], map: "idx_purchase_requests_budget_pool")
+  @@index([project_id], map: "idx_purchase_requests_project")
   @@index([status], map: "idx_purchase_requests_status")
   @@map("purchase_requests")
 }
@@ -1991,6 +1994,7 @@ model Project {
   tasks                   ProjectTask[]
   risks                   ProjectRisk[]
   reimbursements          ReimbursementForm[]
+  purchase_requests       PurchaseRequest[]
   travel_requests         TravelRequest[]
   todo_items              TodoItem[]
   weekly_reports          ProjectLinkOnWeeklyReport[]