feat(auth): 新增 Apple 登录并集成 Sa-Token 鉴权

- AppleServiceImpl：返回完整用户信息并签发 Sa-Token
- 新增 KeyboardUser 实体、Mapper、Service，支持按 subjectId 查询与创建
- GlobalExceptionHandler 统一处理 Sa-Token 未登录异常
- 补充 APPLE_LOGIN_ERROR 等错误码
- 配置文件增加 Sa-Token 相关参数

pom.xml

@@ -104,11 +104,25 @@
             <version>3.6.0</version>
         </dependency>
 
-        <!--        <dependency>-->
-<!--            <groupId>com.alibaba.cloud.ai</groupId>-->
-<!--            <artifactId>spring-ai-alibaba-starter-dashscope</artifactId>-->
-<!--            <version>1.0.0.4</version>-->
-<!--        </dependency>-->
+        <!--   x-file-storage    -->
+        <dependency>
+            <groupId>org.dromara.x-file-storage</groupId>
+            <artifactId>x-file-storage-spring</artifactId>
+            <version>2.3.0</version>
+        </dependency>
+        <!-- amazon-S3-v2       -->
+        <dependency>
+            <groupId>software.amazon.awssdk</groupId>
+            <artifactId>s3</artifactId>
+            <version>2.29.29</version>
+        </dependency>
+        <!-- mailgun-java    -->
+        <dependency>
+            <groupId>com.mailgun</groupId>
+            <artifactId>mailgun-java</artifactId>
+            <version>2.1.1</version>
+        </dependency>
+
         <dependency>
             <groupId>io.jsonwebtoken</groupId>
             <artifactId>jjwt-api</artifactId>