<fix>[kvm]: ZSV-12657 align no-OS stop config description

[zstack-robot-2]

Summary

Align the KVM global-config metadata with the stop strategy used when no guest operating system is detected.

Changes

• Describe `kvm.stop.vm.without.os.by.force.mode` as switching a grace stop to `cold`.
• Keep the configuration key, type, default value, and behavior unchanged.

Testing

• `git diff --check`
• Verified the paired kvmagent change on a ZBS environment with a VM that has an empty root volume.

Resolves: ZSV-12657

sync from gitlab !10575

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 45106c84-8845-4c71-91e6-26d3274008d3

📥 Commits

Reviewing files that changed from the base of the PR and between 81727e9 and 37e3439.

📒 Files selected for processing (1)

• plugin/kvm/src/main/java/org/zstack/kvm/KVMGlobalConfig.java

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Walkthrough

更新 KVM 全局配置项 STOP_VM_WITHOUT_OS_BY_FORCE_MODE 的描述，将停止模式从 force 修改为 cold，其他配置声明保持不变。

Changes

KVM 配置描述

Layer / File(s)	Summary
更新停止模式描述 plugin/kvm/src/main/java/org/zstack/kvm/KVMGlobalConfig.java	将配置项描述中的 force 模式修改为 cold 模式，字段、键值及默认值保持不变。

Estimated code review effort: 1 (Trivial) | ~2 minutes

Poem

小兔捧着配置跑，
force 换成 cold 更明了。
字段键值稳稳在，
描述更新蹦蹦跳。
🐇✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	标题准确概括了本次修改：对 KVM 的 no-OS 停止配置描述进行对齐。
Description check	✅ Passed	描述与变更内容一致，说明了配置元数据更新及保持键、类型和默认值不变。
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch sync/zstackio/codex/zbs-revert-wait-client-release@@3

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