Refacor electron app and add migrations

electron/entities/ReactionEntity.ts

@@ -0,0 +1,22 @@
+import { Entity, PrimaryColumn, Column } from 'typeorm';
+
+@Entity('reactions')
+export class ReactionEntity {
+  @PrimaryColumn('text')
+  id!: string;
+
+  @Column('text')
+  messageId!: string;
+
+  @Column('text', { nullable: true })
+  oderId!: string | null;
+
+  @Column('text', { nullable: true })
+  userId!: string | null;
+
+  @Column('text')
+  emoji!: string;
+
+  @Column('integer')
+  timestamp!: number;
+}