Add new page module and services; refactor existing entities

- Introduced a new page module with associated services.
- Refactored TypeORM entities in user and workspace modules.

server/src/core/page/entities/page.entity.ts

@@ -0,0 +1,88 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  CreateDateColumn,
+  UpdateDateColumn,
+  ManyToOne,
+  JoinColumn,
+  OneToMany,
+  DeleteDateColumn,
+} from 'typeorm';
+import { User } from '../../user/entities/user.entity';
+import { Workspace } from '../../workspace/entities/workspace.entity';
+
+@Entity('pages')
+export class Page {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column({ length: 500, nullable: true })
+  title: string;
+
+  @Column({ type: 'text', nullable: true })
+  content: string;
+
+  @Column({ type: 'text', nullable: true })
+  html: string;
+
+  @Column({ type: 'jsonb', nullable: true })
+  json: any;
+
+  @Column({ nullable: true })
+  slug: string;
+
+  @Column({ nullable: true })
+  icon: string;
+
+  @Column({ nullable: true })
+  coverPhoto: string;
+
+  @Column({ length: 255, nullable: true })
+  editor: string;
+
+  @Column({ length: 255, nullable: true })
+  shareId: string;
+
+  @Column({ type: 'uuid', nullable: true })
+  parentPageId: string;
+
+  @Column()
+  creatorId: string;
+
+  @ManyToOne(() => User)
+  @JoinColumn({ name: 'creatorId' })
+  creator: User;
+
+  @Column()
+  workspaceId: string;
+
+  @ManyToOne(() => Workspace, { onDelete: 'CASCADE' })
+  @JoinColumn({ name: 'workspaceId' })
+  workspace: Workspace;
+
+  @Column({ type: 'boolean', default: false })
+  isLocked: boolean;
+
+  @Column({ length: 255, nullable: true })
+  status: string;
+
+  @Column({ type: 'date', nullable: true })
+  publishedAt: string;
+
+  @CreateDateColumn()
+  createdAt: Date;
+
+  @UpdateDateColumn()
+  updatedAt: Date;
+
+  @DeleteDateColumn({ nullable: true })
+  deletedAt: Date;
+
+  @ManyToOne(() => Page, (page) => page.childPages)
+  @JoinColumn({ name: 'parentPageId' })
+  parentPage: Page;
+
+  @OneToMany(() => Page, (page) => page.parentPage, { onDelete: 'CASCADE' })
+  childPages: Page[];
+}