fix(admin-service): 修复上传版本时isForceUpdate始终为true的问题

问题原因：
- ValidationPipe配置了enableImplicitConversion: true
- FormData发送字符串"false"时，Boolean("false")被隐式转换为true
- @Transform装饰器在隐式转换之后执行，收到的value已经是true

解决方案：
- 在@Transform中使用obj参数获取原始未转换的值
- 手动判断字符串"true"/"false"并正确转换为布尔值

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/services/admin-service/src/api/dto/request/upload-version.dto.ts

@@ -34,12 +34,21 @@ export class UploadVersionDto {
 
   @ApiPropertyOptional({ description: '是否强制更新', default: false })
   @IsOptional()
-  @Transform(({ value }) => {
+  @Transform(({ obj }) => {
+    // Access the raw value directly from the source object
+    // This bypasses enableImplicitConversion which incorrectly converts "false" string to true
+    const rawValue = obj.isForceUpdate
+
     // Handle string "true"/"false" from FormData
-    if (typeof value === 'string') {
-      return value.toLowerCase() === 'true'
+    if (typeof rawValue === 'string') {
+      return rawValue.toLowerCase() === 'true'
     }
-    return value === true
+    // Handle undefined/null - default to false
+    if (rawValue === undefined || rawValue === null) {
+      return false
+    }
+    // Handle actual boolean value
+    return rawValue === true
   })
   @IsBoolean()
   isForceUpdate?: boolean