perf(media): 生产媒体直传阿里云 OSS

生产同构验收确认 server_main_openapi 上传通道在媒体高并发下产生 381 个 502，并将已创建任务的 p95 拉高到 172 秒。\n\n为 request_asset 与 image_result 增加环境配置控制的阿里云 OSS 直传，保留普通上传原通道；使用 Kubernetes Secret 注入凭据，并对签名、重试、场景隔离和生产配置校验增加测试。\n\n验证：Go 全量测试、go vet、OpenAPI、迁移安全检查、Kustomize/Compose 渲染、gofmt 与 git diff --check 均通过；真实 OSS PUT/CDN 读取探针通过且对象已清理。

deploy/kubernetes/production/application.yaml

@@ -62,6 +62,16 @@ spec:
               value: "16"
             - name: AI_GATEWAY_MEDIA_MATERIALIZATION_CONCURRENCY
               value: "8"
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_ID
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_KEY_ID
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_SECRET
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_SECRET_KEY
             - name: POD_NAMESPACE
               valueFrom:
                 fieldRef:
@@ -195,6 +205,16 @@ spec:
               value: "16"
             - name: AI_GATEWAY_MEDIA_MATERIALIZATION_CONCURRENCY
               value: "8"
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_ID
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_KEY_ID
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_SECRET
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_SECRET_KEY
             - name: POD_NAMESPACE
               valueFrom:
                 fieldRef:
@@ -330,6 +350,16 @@ spec:
               value: "24"
             - name: AI_GATEWAY_MEDIA_REQUEST_CONCURRENCY
               value: "24"
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_ID
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_KEY_ID
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_SECRET
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_SECRET_KEY
             - name: POD_NAMESPACE
               valueFrom:
                 fieldRef:
@@ -465,6 +495,16 @@ spec:
               value: "24"
             - name: AI_GATEWAY_MEDIA_REQUEST_CONCURRENCY
               value: "24"
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_ID
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_KEY_ID
+            - name: AI_GATEWAY_MEDIA_OSS_ACCESS_KEY_SECRET
+              valueFrom:
+                secretKeyRef:
+                  name: easyai-oss-backup
+                  key: ACCESS_SECRET_KEY
             - name: POD_NAMESPACE
               valueFrom:
                 fieldRef: