refactor: 重命名SDK为iflow-engine，使用npm包引入第三方引擎

- 将包名从 @fishdingding/bim-engine-sdk 改为 iflow-engine
- 将构建输出文件从 bim-engine-sdk.*.js 改为 iflow-engine.*.js
- 将全局变量从 LyzBimEngineSDK 改为 IflowEngine
- 将第三方引擎SDK从本地引入改为npm包引入 (iflow-engine-base)
- 移除本地 src/engine_base 目录，移至回收站
- 更新所有文档和demo中的引用

demo-vue/package.json

@@ -1,13 +1,13 @@
 {
-  "name": "bim-engine-demo-vue",
+  "name": "iflow-engine-demo-vue",
   "version": "1.0.0",
-  "description": "BIM Engine SDK Vue3 Demo",
+  "description": "iFlow Engine SDK Vue3 Demo",
   "type": "module",
   "scripts": {
     "dev": "vite",
     "build": "vue-tsc && vite build",
     "preview": "vite preview",
-    "copy-sdk": "mkdir -p public/lib && cp ../dist/bim-engine-sdk.umd.js public/lib/ && cp ../dist/bim-engine-sdk.umd.js.map public/lib/ 2>/dev/null || true"
+    "copy-sdk": "mkdir -p public/lib && cp ../dist/iflow-engine.umd.js public/lib/ && cp ../dist/iflow-engine.umd.js.map public/lib/ 2>/dev/null || true"
   },
   "dependencies": {
     "vue": "^3.4.21"