fix: 退回报销支持留痕删除（09-04-reimbursement-state-gap-finance-view）

server/prisma/schema.prisma

@@ -575,6 +575,7 @@ model Department {
 }
 
 model Employee {
+  deleted_reimbursements ReimbursementForm[] @relation("ReimbursementDeletedBy")
   id                        String                    @id @default(uuid()) @db.Uuid
   employee_no               String                    @unique @default(dbgenerated("generate_employee_number()"))
   name                      String
@@ -1441,6 +1442,9 @@ model InventoryCheckItem {
 }
 
 model ReimbursementForm {
+  deleted_at               DateTime?
+  deleted_by               String? @db.Uuid
+  deleted_by_employee      Employee? @relation("ReimbursementDeletedBy", fields: [deleted_by], references: [id], onDelete: Restrict)
   id                       String              @id @default(uuid()) @db.Uuid
   form_number              String?             @unique
   submitter_id             String              @db.Uuid
@@ -1491,6 +1495,7 @@ model ReimbursementForm {
   @@index([status])
   @@index([reimbursement_date])
   @@index([owner_id, status, updated_at], map: "idx_reimbursement_owner_status_updated_at")
+  @@index([deleted_at], map: "idx_reimbursement_forms_deleted_at")
   @@map("reimbursement_forms")
 }