后端与全仓代码质量清理（golangci 扩展集 · 测试质量 · 并发安全 · 文档同步）

代码质量全量清理，零行为变化：golangci 扩展集 13 类 linter（gosec/modernize/perfsprint/canonicalheader/usestdlibvars/wastedassign/intrange/errorlint/forcetypeassert/recvcheck/exhaustive/unparam）全量修复，测试代码质量（testifylint/thelper/usetesting）25→0，frpc 进程生命周期真 bug（进程组击杀）、全仓 go test -race 6 类数据竞争（含 1 个生产竞争）、SPDX license 头补齐 131 文件、前端测试套件 next-intl 迁移后 44 失败→全绿、过期 swagger 文档重新生成、pnpm-workspace 构建审批。

Experiments: #2-#17, #18, #20, #21, #23
Metric: total_issues 108 → 8 (-92.6%)

internal/apps/upload/task/storage_migration.go

@@ -69,7 +69,7 @@ func (h *MigrationHandler) ValidatePayload(payload []byte) ([]byte, error) {
 		return payload, err
 	}
 	if active {
-		return payload, fmt.Errorf("storage migration task is already unresolved")
+		return payload, errors.New("storage migration task is already unresolved")
 	}
 	return normalized, nil
 }
@@ -193,18 +193,18 @@ func migrateObjects(
 	const batchSize = 50
 	const migrationConcurrency = 10
 	const sha256HexLength = 64
-	var migrated int64
+	var migrated atomic.Int64
 	var lastFilePath string
 	for {
 		if err := ctx.Err(); err != nil {
-			return atomic.LoadInt64(&migrated), fmt.Errorf("storage migration canceled: %w", err)
+			return migrated.Load(), fmt.Errorf("storage migration canceled: %w", err)
 		}
 
-		task.AppendLog(ctx, "正在查询待迁移对象批次，当前已完成迁移: %d/%d", atomic.LoadInt64(&migrated), total)
+		task.AppendLog(ctx, "正在查询待迁移对象批次，当前已完成迁移: %d/%d", migrated.Load(), total)
 
 		objects, err := repository.ListDistinctActiveStorageObjects(ctx, lastFilePath, batchSize)
 		if err != nil {
-			return atomic.LoadInt64(&migrated), fmt.Errorf("query source objects: %w", err)
+			return migrated.Load(), fmt.Errorf("query source objects: %w", err)
 		}
 		if len(objects) == 0 {
 			task.AppendLog(ctx, "所有对象迁移完毕")
@@ -223,18 +223,18 @@ func migrateObjects(
 				if err := migrateSingleObject(ctx, sourceBackend, targetBackend, obj, sha256HexLength); err != nil {
 					return err
 				}
-				atomic.AddInt64(&migrated, 1)
+				migrated.Add(1)
 				return nil
 			})
 		}
 
 		if err := g.Wait(); err != nil {
-			return atomic.LoadInt64(&migrated), err
+			return migrated.Load(), err
 		}
 
-		task.AppendLog(ctx, "当前批次迁移完成。迁移进度: %d/%d", atomic.LoadInt64(&migrated), total)
+		task.AppendLog(ctx, "当前批次迁移完成。迁移进度: %d/%d", migrated.Load(), total)
 	}
-	return atomic.LoadInt64(&migrated), nil
+	return migrated.Load(), nil
 }
 
 func migrateSingleObject(