feat(oauth): 允许替换已失效的活跃 OAuth 账号并同步 status_snapshot

- 活跃但 token 已过期或刷新失败的重复账号视为可替换
- 清除失效标记、刷新配额时同步更新 status_snapshot.oauth
- oauth_invalid 清除接口同时识别 invalid_at 与 invalid_reason 两种标记
- 批量导入任务状态区分 created_count / replaced_count，前端据此展示新增/替换统计
- 补充重复替换场景的集成测试，用量测试等待超时从 10s 提升到 30s 以适应并行压力

apps/aether-gateway/src/handlers/shared/mod.rs

@@ -23,7 +23,8 @@ pub(crate) use self::catalog::{
     default_provider_key_status_snapshot, effective_catalog_encryption_key,
     encrypt_catalog_secret_with_fallbacks, masked_catalog_api_key, parse_catalog_auth_config_json,
     provider_catalog_key_supports_format, provider_key_health_summary,
-    provider_key_status_snapshot_payload, sync_provider_key_quota_status_snapshot,
+    provider_key_status_snapshot_payload, sync_provider_key_oauth_status_snapshot,
+    sync_provider_key_quota_status_snapshot,
 };
 pub(crate) use self::email_templates::{
     admin_email_template_definition, admin_email_template_html_key,