perf(storage): 极简化任务历史并增加保留治理

停止持久化 provider 原始响应、兼容响应快照、attempt/event/outbox 重复 JSON，并由标准任务结果动态生成 Kling/Keling/Volces 兼容响应。

增加事件去重与预算、极简 callback 投递、7/30 天分批清理、安全删除条件、并发迁移索引及可实际恢复的任务域排除备份。历史清理默认关闭，待兼容协议和异步恢复在线验证后单独启用。

验证：Go 全量测试与 go vet、PostgreSQL 18 集成与实际备份恢复、迁移安全测试、bash -n、ShellCheck、Compose 配置和人工发布脚本测试均通过。

docker-compose.yml

@@ -19,6 +19,11 @@ x-api-environment: &api-environment
   TASK_PROGRESS_CALLBACK_URL: ${AI_GATEWAY_COMPOSE_TASK_PROGRESS_CALLBACK_URL:-http://host.docker.internal:3000/internal/platform/task-progress-callbacks}
   TASK_PROGRESS_CALLBACK_TIMEOUT_MS: ${TASK_PROGRESS_CALLBACK_TIMEOUT_MS:-5000}
   TASK_PROGRESS_CALLBACK_MAX_ATTEMPTS: ${TASK_PROGRESS_CALLBACK_MAX_ATTEMPTS:-10}
+  AI_GATEWAY_TASK_CLEANUP_ENABLED: ${AI_GATEWAY_TASK_CLEANUP_ENABLED:-false}
+  AI_GATEWAY_TASK_RETENTION_DAYS: ${AI_GATEWAY_TASK_RETENTION_DAYS:-30}
+  AI_GATEWAY_TASK_ANALYSIS_RETENTION_DAYS: ${AI_GATEWAY_TASK_ANALYSIS_RETENTION_DAYS:-7}
+  AI_GATEWAY_TASK_CLEANUP_INTERVAL_SECONDS: ${AI_GATEWAY_TASK_CLEANUP_INTERVAL_SECONDS:-300}
+  AI_GATEWAY_TASK_CLEANUP_BATCH_SIZE: ${AI_GATEWAY_TASK_CLEANUP_BATCH_SIZE:-1000}
   CORS_ALLOWED_ORIGIN: ${AI_GATEWAY_COMPOSE_CORS_ALLOWED_ORIGIN:-http://localhost:5178,http://127.0.0.1:5178}
   AI_GATEWAY_PUBLIC_BASE_URL: ${AI_GATEWAY_COMPOSE_PUBLIC_BASE_URL:-http://localhost:8088}
   AI_GATEWAY_WEB_BASE_URL: ${AI_GATEWAY_COMPOSE_WEB_BASE_URL:-http://localhost:5178}