增加 DeepSeek Harness 市场源支持

- package.json 声明 dsh.bundle 与 dsh 引擎范围，供 DSH 作为 bundle 安装
- cordis.patch.yml 与 lib/index.js 注册只指向本包 skills 目录的技能提供方
- index.json 提供 format 1 市场索引，DSH 可通过索引地址发现并安装
- README 补充 DSH 安装方式与三处版本号的同步说明

index.json

@@ -0,0 +1,40 @@
+{
+  "format": 1,
+  "title": { "en": "zlh-agent-market", "zh": "左林豪的习惯约定" },
+  "description": {
+    "en": "Reusable working conventions for AI coding agents.",
+    "zh": "给 AI 编码助手用的通用协作约定。"
+  },
+  "plugins": [
+    {
+      "name": "engineering-conventions",
+      "title": { "en": "Engineering conventions", "zh": "工程协作约定" },
+      "description": {
+        "en": "Look for existing implementations first, align before touching shared code, update docs in the same change, verify minimally, report progress on long tasks, write structured commit messages.",
+        "zh": "先找现成实现、公共代码改动先对齐、改实现同轮改文档、最小验证、长任务报进度、规范提交信息。"
+      },
+      "author": "左林豪",
+      "homepage": "https://www.zlhhh.com/ZLH/engineering-conventions",
+      "repository": {
+        "url": "https://www.zlhhh.com/ZLH/engineering-conventions"
+      },
+      "metadata": {
+        "keywords": ["engineering", "conventions", "workflow", "git"]
+      },
+      "versions": [
+        {
+          "version": "1.1.0",
+          "publishTimestamp": 1793145600,
+          "source": {
+            "type": "git",
+            "url": "https://www.zlhhh.com/ZLH/engineering-conventions",
+            "commit": "0000000000000000000000000000000000000000"
+          },
+          "engines": {
+            "dsh": ">=0.2.0-rc.2"
+          }
+        }
+      ]
+    }
+  ]
+}