[ISSUE #15201] Fix skill meta description sync on upload

[Jholly2008]

Please do not create a Pull Request without creating an issue first.

What is the purpose of the change

Fixes #15201.

This PR fixes inconsistent AI skill descriptions between the skill list page and the skill detail/version page after uploading a new ZIP version for an existing skill.

Previously, the uploaded SKILL.md frontmatter description was saved into the version data, but the existing skill meta row only updated editingVersion. The meta description used by the list page could remain stale while the detail/version page showed the new uploaded description.

Brief changelog

• Synchronize a non-blank draft description into the existing skill meta row when uploading a ZIP draft for an existing skill.
• Preserve the existing meta description when the incoming draft description is blank.
• Add a regression unit test for existing skill ZIP upload description synchronization.

Verifying this change

• mvn -B clean package apache-rat:check spotbugs:check -DskipTests
• mvn -pl ai -am "-Dtest=SkillOperationServiceImplTest#testUploadSkillFromZipShouldSyncMetaDescriptionForExistingSkill" "-Dsurefire.failIfNoSpecifiedTests=false" test
• mvn -pl ai -am "-Dtest=SkillOperationServiceImplTest" "-Dsurefire.failIfNoSpecifiedTests=false" test
• mvn -pl ai -am "-Dtest=AiResourceManagerTest" "-Dsurefire.failIfNoSpecifiedTests=false" test
• mvn -pl ai -am "-Dtest=SkillOperationServiceImplTest,AiResourceManagerTest" "-Dsurefire.failIfNoSpecifiedTests=false" test
• git diff --check

mvn clean install was also attempted locally, but it failed in existing nacos-common tests under JDK 21.0.1 with IllegalAccessException: static final field has no write access, unrelated to this change.

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[github-actions]

Thanks for your this PR. 🙏
Please check again for your PR changes whether contains any usage/api/configuration change such as Add new API , Add new configuration, Change default value of configuration.
If so, please add or update documents(markdown type) in docs/next/ for repository nacos-group/nacos-group.github.io

---

感谢您提交的PR。 🙏
请再次查看您的PR内容，确认是否包含任何使用方式/API/配置参数的变更，如：新增API、新增配置参数、修改默认配置等操作。
如果是，请确保在提交之前，在仓库nacos-group/nacos-group.github.io中的docs/next/目录下添加或更新文档（markdown格式）。

[Jholly2008]

This PR only fixes internal metadata synchronization for existing AI skill ZIP uploads. It does not add or change any API, configuration, default value, or user-facing usage. Therefore no docs update is required.

[KomachiSion]

PR 主路径修复是对的，但 description 为空时的 CAS retry 语义确实有问题。第一次 CAS 失败后，如果并发请求已经把 ai_resource.c_desc 更新成新值，当前代码第二次重试仍会用最初 existedMeta.getDesc() 里的旧描述写回去，覆盖掉最新描述。

建议把 description 是否非空作为判断：

boolean syncDescription = StringUtils.isNotBlank(description);
newValue.setDesc(syncDescription ? description : existedMeta.getDesc());

...
if (!syncDescription) {
    nv.setDesc(latest.getDesc());
}

这样非空描述表示“本次操作要主动同步描述”，空描述表示“本次只更新 versionInfo，desc 应跟随 latest 保留”。

影响范围：skill 和 agentspec 都受这个通用方法影响；prompt 现有 meta 创建草稿路径没走这个 existing-meta 分支，基本不受本 PR 影响。建议补一个 AiResourceManagerTest：空 description、第一次 CAS 失败、retry find 返回 latest.desc = new-desc，最终第二次 updateMetaCas 捕获到的 desc 应该是 new-desc。

[Jholly2008]

Fixed the CAS retry behavior from the review comment.

Changes:

• Non-blank description now means the draft upload should actively sync the meta description.
• Blank description now means the operation only updates versionInfo; on CAS retry, desc is refreshed from latest meta to avoid overwriting concurrent description updates.
• Added AiResourceManagerTest#initOrUpdateMetaForDraftShouldPreserveLatestDescriptionWhenDescriptionBlankOnRetry.

Verified with:

• mvn -pl ai -am "-Dtest=AiResourceManagerTest#initOrUpdateMetaForDraftShouldPreserveLatestDescriptionWhenDescriptionBlankOnRetry" "-Dsurefire.failIfNoSpecifiedTests=false" test
• mvn -pl ai -am "-Dtest=AiResourceManagerTest,SkillOperationServiceImplTest" "-Dsurefire.failIfNoSpecifiedTests=false" test
• git diff --check

[codecov-commenter]

Codecov Report

❌ Patch coverage is 85.00000% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...a/nacos/ai/service/resource/AiResourceManager.java	85.00%	1 Missing and 2 partials ⚠️

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