[CI] Cloud Engine clickhouse/damengdb/gaussdb matrix retains 4 deterministic failures

[khalildai]

Evidence

Scheduled Cloud E2E Engine run 30663229523 on release-2.2 (f1e03027c8c34e30a86c0105157ed20f3f09d83f) completed 14 passed / 4 failed across 18 engine-mode combinations:

• clickhouse cluster 22.9.4: database operation, 11/12
• damengdb realtime-replication 8.1.3-26-20240821: create operation, 0/13
• gaussdb replication 2.23.1: backup operation, 12/13
• gaussdb standalone 2.23.1: backup operation, 10/11

FoundationDB (single/double/triple), StarRocks shared-data and the other ClickHouse/Dameng combinations passed. The same matrix family was also red on 2026-07-17 (run 29610939498), although the failure set has improved from 13 to 4. Exact open-issue searches for these engine/version/operation signatures returned no canonical tracker.

Expected closeout

1. Classify each remaining failure as engine catalog/configuration drift, Cloud control-plane behavior, or test-contract defect.
2. Repair or explicitly quarantine only unsupported combinations with documented ownership/reason.
3. Preserve coverage for the 14 passing combinations and validate through the next natural scheduled matrix.

No rerun, environment mutation, release, deployment, or production change is authorized by this issue.

[khalildai]

后续自然 scheduled 样本补充（不回填原固定窗；无 rerun/environment mutation）：

• run 30716974796，同一 release-2.2 main exact f1e03027c8c34e30a86c0105157ed20f3f09d83f，于 2026-08-02T01:20Z 自然终态 failure。
• 18 个 engine-mode 组合为 12 passed / 6 failed；新失败集合：
  • Doris disaggregated 2.1.6：create，0/10
  • Doris disaggregated 4.0.7：hscale，9/10
  • Doris disaggregated 4.1.3：hscale，3/10
  • Kingbase replication 8.6.8：promote，7/11
  • Kingbase replication 9.3.15：promote，3/11
  • Kingbase standalone 9.3.15：backup，9/10
• RabbitMQ 四种组合、RocketMQ 两种、Zookeeper 两种，以及 Doris aggregated 三种、Kingbase standalone 8.6.8 均通过。

这说明问题仍是随 scheduled engine batch 暴露的确定性产品/目录/操作合同，不是 self-hosted runner 或容量。建议本 Issue 的验收矩阵同时覆盖原 ClickHouse/Dameng/GaussDB 四项与本次 Doris/Kingbase 六项，并逐项标注支持状态；不靠盲重跑缩小失败集合。