chore: initialize standalone UPM package

package.json

@@ -0,0 +1,25 @@
+{
+  "name": "com.cneicy.shrink-tutorial",
+  "version": "0.1.0",
+  "displayName": "ShrinkTutorial",
+  "description": "面向 Unity 的互动式新手引导系统，提供数据驱动教程、遮罩挖洞、动态锚点、步骤条件与运行时调度。",
+  "unity": "2022.3",
+  "dependencies": {
+    "com.unity.textmeshpro": "3.0.7",
+    "com.unity.ugui": "1.0.0",
+    "com.unity.modules.physics": "1.0.0"
+  },
+  "keywords": [
+    "tutorial",
+    "guide",
+    "onboarding",
+    "ui",
+    "workflow"
+  ],
+  "author": {
+    "name": "cneicy",
+    "url": "https://git.crash.work/ShrinkSDK"
+  },
+  "documentationUrl": "https://git.crash.work/ShrinkSDK/ShrinkTutorial",
+  "changelogUrl": "https://git.crash.work/ShrinkSDK/ShrinkTutorial/src/branch/main/CHANGELOG.md"
+}