feat(skills): 新增 configuring-compute 技能 (#37)

## 中文

新增官方内置技能 `configuring-compute`：让平台内智能体能帮用户配置算力供应商与 API Key。

- 完整流程：查看配置 → 创建/更新 provider → 写入密钥（只写端点）→ verify-key 验证 → 启用/同步模型 →
POST /api/compute/reload 刷新
- 安全模型写入技能文本：密钥只写不读，禁止读取 secrets.json 或尝试读回已有 key
- 加入 builtin-skills.json 清单；manifest version 1.2.6 → 1.2.7

依赖 desirecore 主仓库的配套 PR（掩码脱敏 + reload 端点）。

## English

Add the official builtin skill `configuring-compute`: enables
in-platform agents to configure compute providers and API keys for the
user.

- Full flow: inspect config → create/update provider → write key
(write-only endpoint) → verify-key → enable/sync models → POST
/api/compute/reload
- Security model embedded in the skill text: keys are write-only;
reading secrets.json or existing keys is forbidden
- Added to builtin-skills.json manifest; manifest version 1.2.6 → 1.2.7

Depends on the companion PR in the desirecore main repo (key masking +
reload endpoint).

manifest.json

@@ -1,6 +1,6 @@
 {
   "name": "DesireCore Official Market",
-  "version": "1.2.6",
+  "version": "1.2.7",
   "schemaVersion": "1.1.0",
   "supportedLocales": ["zh-CN", "en-US"],
   "defaultLocale": "en-US",
@@ -27,8 +27,8 @@
   },
   "stats": {
     "totalAgents": 1,
-    "totalSkills": 25,
-    "lastUpdated": "2026-06-15"
+    "totalSkills": 26,
+    "lastUpdated": "2026-07-07"
   },
   "features": [
     "verified-only",