feat: add weapp-tailwindcss integration for uni-app

Install required dependencies, configure PostCSS and Vite plugin, create global app.css entry file, import styles in main.js, and add postinstall patch script.

package.json

@@ -2,6 +2,7 @@
   "name": "YGChatCS",
   "version": "1.0.0",
   "scripts": {
+    "postinstall": "node ./node_modules/weapp-tailwindcss/bin/weapp-tailwindcss.js patch",
     "dev:app": "uni -p app",
     "dev:app-android": "uni -p app-android",
     "dev:app-ios": "uni -p app-ios",
@@ -70,10 +71,13 @@
     "@dcloudio/uni-cli-shared": "3.0.0-4070620250821001",
     "@dcloudio/uni-stacktracey": "3.0.0-4070620250821001",
     "@dcloudio/vite-plugin-uni": "3.0.0-4070620250821001",
+    "@tailwindcss/postcss": "^4.3.0",
     "@vue/runtime-core": "^3.4.21",
     "@vue/tsconfig": "^0.1.3",
     "sass": "1.58.3",
-    "vite": "5.2.8"
+    "tailwindcss": "^4.3.0",
+    "vite": "5.2.8",
+    "weapp-tailwindcss": "^4.12.0"
   },
   "packageManager": "yarn@1.22.22+sha512.a6b2f7906b721bba3d67d4aff083df04dad64c399707841b7acf00f6b133b7ac24255f2652fa22ae3534329dc6180534e98d17432037ff6fd140556e2bb3137e"
 }