feat(database): refactor entities and relationships for service management

src/entity/follow.entity.ts

@@ -1,4 +1,5 @@
-import { Column, Entity, PrimaryGeneratedColumn } from "typeorm";
+import { Column, Entity, JoinColumn, ManyToOne, PrimaryGeneratedColumn } from "typeorm";
+import { Service } from "./service.entity";
 
 @Entity({name: 'follows'})
 export class Follow {
@@ -8,8 +9,12 @@ export class Follow {
     @Column()
     user_discord: string;
 
+    @ManyToOne(() => Service, service => service.follows)
+    @JoinColumn({name: 'serviceId'})
+    service: Service;
+
     @Column()
-    host: string;
+    serviceId: number;
 
     @Column({default: false})
     enable: boolean;