feat(aiot): 集成腾讯云 COS Java SDK，WVP 直接生成 presigned URL

- pom.xml 新增 cos_api 5.6.227 依赖
- 新建 CosUtil 工具类（读取 ai.cos.* 配置，初始化 COSClient，生成预签名 URL）
- application-dev.yml / application-docker.yml 增加 ai.cos 配置段

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pom.xml

@@ -422,6 +422,13 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+
+        <!-- 腾讯云 COS SDK（截图/告警图片 presign） -->
+        <dependency>
+            <groupId>com.qcloud</groupId>
+            <artifactId>cos_api</artifactId>
+            <version>5.6.227</version>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/com/genersoft/iot/vmp/aiot/util/CosUtil.java

@@ -0,0 +1,96 @@
+package com.genersoft.iot.vmp.aiot.util;
+
+import com.qcloud.cos.COSClient;
+import com.qcloud.cos.ClientConfig;
+import com.qcloud.cos.auth.BasicCOSCredentials;
+import com.qcloud.cos.auth.COSCredentials;
+import com.qcloud.cos.http.HttpProtocol;
+import com.qcloud.cos.region.Region;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import jakarta.annotation.PostConstruct;
+import jakarta.annotation.PreDestroy;
+import java.net.URL;
+import java.util.Date;
+
+@Slf4j
+@Component
+public class CosUtil {
+
+    @Value("${ai.cos.secret-id:${COS_SECRET_ID:}}")
+    private String secretId;
+
+    @Value("${ai.cos.secret-key:${COS_SECRET_KEY:}}")
+    private String secretKey;
+
+    @Value("${ai.cos.region:${COS_REGION:ap-beijing}}")
+    private String region;
+
+    @Value("${ai.cos.bucket:${COS_BUCKET:}}")
+    private String bucket;
+
+    private COSClient cosClient;
+
+    @PostConstruct
+    public void init() {
+        if (secretId == null || secretId.isEmpty() || secretKey == null || secretKey.isEmpty()) {
+            log.warn("[COS] 未配置 COS 凭证（COS_SECRET_ID/COS_SECRET_KEY），图片代理功能不可用");
+            return;
+        }
+        if (bucket == null || bucket.isEmpty()) {
+            log.warn("[COS] 未配置 COS_BUCKET，图片代理功能不可用");
+            return;
+        }
+        try {
+            COSCredentials cred = new BasicCOSCredentials(secretId, secretKey);
+            ClientConfig config = new ClientConfig(new Region(region));
+            config.setHttpProtocol(HttpProtocol.https);
+            cosClient = new COSClient(cred, config);
+            log.info("[COS] 客户端初始化成功: region={}, bucket={}", region, bucket);
+        } catch (Exception e) {
+            log.error("[COS] 客户端初始化失败: {}", e.getMessage());
+        }
+    }
+
+    @PreDestroy
+    public void destroy() {
+        if (cosClient != null) {
+            cosClient.shutdown();
+        }
+    }
+
+    /**
+     * 生成预签名下载 URL
+     *
+     * @param objectKey COS 对象路径
+     * @param expireSeconds 有效期（秒）
+     * @return presigned URL，失败返回 null
+     */
+    public String generatePresignedUrl(String objectKey, int expireSeconds) {
+        if (cosClient == null) {
+            log.warn("[COS] 客户端未初始化，无法生成 presigned URL");
+            return null;
+        }
+        try {
+            Date expiration = new Date(System.currentTimeMillis() + expireSeconds * 1000L);
+            URL url = cosClient.generatePresignedUrl(bucket, objectKey, expiration);
+            return url.toString();
+        } catch (Exception e) {
+            log.error("[COS] 生成 presigned URL 失败: key={}, error={}", objectKey, e.getMessage());
+            return null;
+        }
+    }
+
+    /**
+     * 生成预签名下载 URL（默认 1 小时有效）
+     */
+    public String generatePresignedUrl(String objectKey) {
+        return generatePresignedUrl(objectKey, 3600);
+    }
+
+    public boolean isAvailable() {
+        return cosClient != null;
+    }
+}

src/main/resources/application-dev.yml

@@ -124,6 +124,11 @@ ai:
   screenshot:
     # Edge截图回调地址（WVP外部可访问地址，Edge通过此地址回调截图结果）
     callback-url: http://124.221.55.225:18080
+  cos:
+    secret-id:
+    secret-key:
+    region: ap-beijing
+    bucket:
   mqtt:
     # MQTT推送开关
     enabled: false

src/main/resources/application-docker.yml

@@ -86,6 +86,11 @@ ai:
     enabled: ${AI_SERVICE_ENABLED:false}
   screenshot:
     callback-url: ${AI_SCREENSHOT_CALLBACK_URL:}
+  cos:
+    secret-id: ${COS_SECRET_ID:}
+    secret-key: ${COS_SECRET_KEY:}
+    region: ${COS_REGION:ap-beijing}
+    bucket: ${COS_BUCKET:}
   mqtt:
     enabled: ${AI_MQTT_ENABLED:false}
     broker: ${AI_MQTT_BROKER:tcp://127.0.0.1:1883}