chore: initialize standalone UPM package

package.json

@@ -0,0 +1,23 @@
+{
+  "name": "com.cneicy.shrink-command",
+  "version": "0.2.0",
+  "displayName": "ShrinkCommand",
+  "description": "独立于网络层的 Unity 命令系统，提供路径式命令、权限、帮助输出与属性式注册。",
+  "unity": "2022.3",
+  "dependencies": {
+    "com.cneicy.shrink-shared-codegen": "0.1.0",
+    "com.cysharp.unitask": "2.5.10"
+  },
+  "keywords": [
+    "command",
+    "console",
+    "debug",
+    "tooling"
+  ],
+  "author": {
+    "name": "cneicy",
+    "url": "https://git.crash.work/ShrinkSDK"
+  },
+  "documentationUrl": "https://git.crash.work/ShrinkSDK/ShrinkCommand",
+  "changelogUrl": "https://git.crash.work/ShrinkSDK/ShrinkCommand/src/branch/main/CHANGELOG.md"
+}