fix nullable column types for postgres migration

src/entities/business.entity.ts

@@ -25,13 +25,13 @@ export class BusinessEntity {
   @Column({ unique: true, length: 120 })
   slug!: string;
 
-  @Column({ nullable: true, length: 500 })
+  @Column({ type: 'varchar', nullable: true, length: 500 })
   description!: string | null;
 
-  @Column({ nullable: true, length: 20 })
+  @Column({ type: 'varchar', nullable: true, length: 20 })
   contactPhone!: string | null;
 
-  @Column({ nullable: true, length: 500 })
+  @Column({ type: 'varchar', nullable: true, length: 500 })
   address!: string | null;
 
   @Column({ type: 'double precision', nullable: true })

src/entities/service-template.entity.ts

@@ -22,7 +22,7 @@ export class ServiceTemplateEntity {
   @Column({ unique: true, length: 120 })
   slug!: string;
 
-  @Column({ nullable: true, length: 400 })
+  @Column({ type: 'varchar', nullable: true, length: 400 })
   description!: string | null;
 
   @Column({ type: 'int', default: 30 })

src/entities/user.entity.ts

@@ -23,7 +23,7 @@ export class UserEntity {
   @Column({ unique: true, length: 20 })
   mobile!: string;
 
-  @Column({ nullable: true, length: 150 })
+  @Column({ type: 'varchar', nullable: true, length: 150 })
   fullName!: string | null;
 
   @Column({ type: 'enum', enum: UserRole, default: UserRole.CUSTOMER })