factory and restructure view models

src/entity/unit/wearable/wearable.ts

@@ -29,7 +29,7 @@ export class wearable {
   wearableTypeId: string;
 
   @Column()
-  wearerId: string;
+  wearerId?: string;
 
   @ManyToOne(() => wearableType, {
     nullable: false,
@@ -39,11 +39,11 @@ export class wearable {
   wearableType: wearableType;
 
   @ManyToOne(() => member, {
-    nullable: false,
+    nullable: true,
     onDelete: "SET NULL",
     onUpdate: "RESTRICT",
   })
-  wearer: member;
+  wearer?: member;
 
   @OneToMany(() => damageReport, (d) => d.wearable, { cascade: ["insert"] })
   reports: damageReport[];