feat: 收录应用开发发布技能与双语示例 (#214)

## 中文

新增按需调用的内置技能 `app-developer`（应用开发与发布）：中英正文、sidecar、MIT 许可、静态与服务两个通用工作台示例，以及作者接口与分发参考，并登记进 `builtin-skills.json`。作者管理优先使用 AppManage 的有限动作，执行前须通过 `authoring_capabilities` 确认 `app-authoring-v1`，能力不可用时停止受影响的操作；外部 Node/Docker 运行时、托管、Git 服务与数据库的条款和可能费用已在发现文案、compatibility 与正文披露。另将 dev-environment-setup 探测参考中的三处用户 home 示例改为通用路径。

与 #220、#212 合入后的 main 解决 manifest 冲突：技能总数 144，市场版本 1.5.13。验证：catalog 与 i18n 校验 0 errors / 106 warnings（含新技能尚未 ref-bound review 的治理提醒），translate --check 与 git diff --check 通过；远端 validate、translate、CodeQL 通过。Copilot 因额度用尽未能审查。

## English

Add the on-demand builtin `app-developer` skill (application development and publishing): English/Chinese bodies, sidecar, MIT license, static and service workbench examples, plus authoring-interface and distribution references, registered in `builtin-skills.json`. Authoring prefers AppManage's finite actions and must confirm `app-authoring-v1` through `authoring_capabilities` first, stopping affected operations when the capability is unavailable. External Node/Docker runtime, hosting, Git service and database terms and possible costs are disclosed. Three user-home examples in the dev-environment-setup probe reference are neutralized.

The manifest conflict with main after #220 and #212 is resolved: 144 skills, market version 1.5.13. Catalog and i18n validation report 0 errors with 106 warnings (including the new skill's pending ref-bound review notice); translate --check and git diff --check pass; remote validate, translate and CodeQL passed. Copilot could not review because of its quota limit.

builtin-skills.json

@@ -1,5 +1,6 @@
 {
   "skills": [
+    "app-developer",
     "baidu-poi-search",
     "ccgp-gov-procurement",
     "clone-agent",