feat(Sora): 直连生成并移除sora2api依赖

实现直连 Sora 客户端、媒体落地与清理策略\n更新网关与前端配置以支持 Sora 平台\n补齐单元测试与契约测试，新增 curl 测试脚本\n\n测试: go test ./... -tags=unit

backend/cmd/server/wire.go

@@ -67,6 +67,7 @@ func provideCleanup(
 	opsAlertEvaluator *service.OpsAlertEvaluatorService,
 	opsCleanup *service.OpsCleanupService,
 	opsScheduledReport *service.OpsScheduledReportService,
+	soraMediaCleanup *service.SoraMediaCleanupService,
 	schedulerSnapshot *service.SchedulerSnapshotService,
 	tokenRefresh *service.TokenRefreshService,
 	accountExpiry *service.AccountExpiryService,
@@ -100,6 +101,12 @@ func provideCleanup(
 				}
 				return nil
 			}},
+			{"SoraMediaCleanupService", func() error {
+				if soraMediaCleanup != nil {
+					soraMediaCleanup.Stop()
+				}
+				return nil
+			}},
 			{"OpsAlertEvaluatorService", func() error {
 				if opsAlertEvaluator != nil {
 					opsAlertEvaluator.Stop()