fix(skills): update-agent 示例字段名修正 + get 返回示例对齐真实输出 (#53)

## 摘要 / Summary

### 中文

market#52 的修正:update-agent
附录示例使用了错误的字段名(`communicationStyle`/`must`),照示例调用会被 ManageAgent 的 Ajv
校验(additionalProperties: false)直接拒绝;`personality` 示例应为字符串数组。同时把 `get`
的返回示例对齐真实输出格式(`## persona.md` / `## principles.md` 段落含分层 markdown 原文,对应
desirecore#1230),并在附录固定列出结构化字段名清单。update-agent 3.1.1,manifest 1.2.11。

### English

Correction to market#52: the update-agent appendix examples used wrong
field names (`communicationStyle`/`must`) that ManageAgent's Ajv
validation (additionalProperties: false) would reject outright;
`personality` must be a string array. The `get` response example is
aligned with the actual output format (`## persona.md` / `##
principles.md` sections, per desirecore#1230), and the appendix now
lists the fixed structured field names. update-agent 3.1.1, manifest
1.2.11.

manifest.json

@@ -1,6 +1,6 @@
 {
   "name": "DesireCore Official Market",
-  "version": "1.2.10",
+  "version": "1.2.11",
   "schemaVersion": "1.1.0",
   "supportedLocales": ["zh-CN", "en-US"],
   "defaultLocale": "en-US",