task-152: 清理失败吞异常记指标（aiimage.temp-cleanup.failed 计数、日志+指标均不阻断主流程、按路径隔离、无重试循环）+ 8 条测试

backend-java/src/main/java/com/nanri/aiimage/modules/file/service/LocalTempCleanupService.java

@@ -2,8 +2,10 @@ package com.nanri.aiimage.modules.file.service;
 
 import cn.hutool.core.io.FileUtil;
 import com.nanri.aiimage.config.StorageProperties;
+import io.micrometer.core.instrument.MeterRegistry;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Service;
 
@@ -20,6 +22,7 @@ public class LocalTempCleanupService {
 
     private static final Pattern ROOT_TEMP_FILE_PATTERN = Pattern.compile("^[a-fA-F0-9]{32}(\\.[^.]+)?$");
     private static final String TRANSIENT_PAYLOAD_DIR_NAME = "transient-payload";
+    private static final String CLEANUP_FAILED_METRIC = "aiimage.temp-cleanup.failed";
     private static final List<String> RESULT_DIR_NAMES = List.of(
             "dedupe-result",
             "convert-result",
@@ -32,6 +35,10 @@ public class LocalTempCleanupService {
 
     private final StorageProperties storageProperties;
 
+    /** 指标注册表（可选注入：无注册表时仅记日志，不影响清理）。 */
+    @Autowired(required = false)
+    private MeterRegistry meterRegistry;
+
     @Scheduled(cron = "${aiimage.storage.cleanup-cron:0 0 */6 * * *}")
     public void cleanupLocalTempDir() {
         if (!storageProperties.isCleanupEnabled()) {
@@ -78,7 +85,7 @@ public class LocalTempCleanupService {
                     deleteEmptyDirectories(child, tempDir);
                 }
             } catch (Exception ex) {
-                log.warn("local temp cleanup failed: path={}", child.getAbsolutePath(), ex);
+                handleCleanupFailure(child, ex);
             }
         }
 
@@ -125,6 +132,23 @@ public class LocalTempCleanupService {
         return ROOT_TEMP_FILE_PATTERN.matcher(file.getName()).matches();
     }
 
+    /**
+     * 清理失败处理：记录日志与失败指标，不抛异常、不重试（下一轮定时清理自然重试）。
+     * 单个条目失败不影响其余条目的清理。
+     */
+    void handleCleanupFailure(File child, Exception ex) {
+        log.warn("local temp cleanup failed: path={}", child == null ? null : child.getAbsolutePath(), ex);
+        try {
+            if (meterRegistry != null && child != null) {
+                meterRegistry.counter(CLEANUP_FAILED_METRIC, "path", child.getName()).increment();
+            }
+        } catch (Exception metricEx) {
+            // 指标记录失败也不阻断清理主流程
+            log.warn("local temp cleanup metric record failed path={}",
+                    child == null ? null : child.getName(), metricEx);
+        }
+    }
+
     private boolean isExpired(File file, Instant expireBefore) {
         // 以 mtime 近似最后访问（TempFileMetadata 回退语义，与现状一致）
         return TempFileMetadata.lastAccessTime(file).isBefore(expireBefore);