✨ feat(file): add user relationship and update user ID type

- change uploadUserId from string to number type
- add ManyToOne relationship with UserEntity
- update FileSchema, CreateFileDto and UpdateFileDto to use numeric user ID
- update example values from string "U1001" to number 1

src/server/modules/files/file.entity.ts

@@ -1,5 +1,6 @@
-import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { Entity, PrimaryGeneratedColumn, Column, Index, ManyToOne, JoinColumn } from 'typeorm';
 import { z } from '@hono/zod-openapi';
+import { UserEntity } from '@/server/modules/users/user.entity';
 
 @Entity('file')
 export class File {
@@ -21,8 +22,12 @@ export class File {
   @Column({ name: 'description', type: 'text', nullable: true })
   description?: string;
 
-  @Column({ name: 'upload_user_id', type: 'varchar', length: 50 })
-  uploadUserId!: string;
+  @Column({ name: 'upload_user_id', type: 'int', unsigned: true })
+  uploadUserId!: number;
+
+  @ManyToOne(() => UserEntity)
+  @JoinColumn({ name: 'upload_user_id', referencedColumnName: 'id' })
+  uploadUser!: UserEntity;
 
   @Column({ name: 'upload_time', type: 'datetime' })
   uploadTime!: Date;
@@ -67,9 +72,9 @@ export const FileSchema = z.object({
     description: '文件描述',
     example: '2023年度项目计划书' 
   }),
-  uploadUserId: z.string().max(50).openapi({ 
+  uploadUserId: z.number().int().positive().openapi({
     description: '上传用户ID',
-    example: 'U1001' 
+    example: 1
   }),
   uploadTime: z.date().openapi({ 
     description: '上传时间',
@@ -110,9 +115,9 @@ export const CreateFileDto = z.object({
     description: '文件描述',
     example: '2023年度项目计划书'
   }),
-  uploadUserId: z.string().max(50).openapi({
+  uploadUserId: z.number().int().positive().openapi({
     description: '上传用户ID',
-    example: 'U1001'
+    example: 1
   }),
   lastUpdated: z.coerce.date().nullable().optional().openapi({
     description: '最后更新时间',
@@ -141,9 +146,9 @@ export const UpdateFileDto = z.object({
     description: '文件描述',
     example: '2023年度项目计划书（修订版）' 
   }),
-  uploadUserId: z.string().max(50).optional().openapi({ 
+  uploadUserId: z.number().int().positive().optional().openapi({
     description: '上传用户ID',
-    example: 'U1001' 
+    example: 1
   }),
   uploadTime: z.coerce.date().optional().openapi({ 
     description: '上传时间',