chore: 清理未使用的模板编辑功能及相关依赖

移除模板编辑相关组件、工具函数和类型定义，并删除不再需要的第三方依赖包。此功能已不再使用，清理以减少项目体积和复杂度。

- 删除模板编辑页面及其所有子组件（left-tree、middle-book、right-topic等）
- 移除PDF转换、图片裁剪、数学公式编辑等工具函数
- 清理富文本编辑器组件及相关类型定义
- 从package.json移除@formkit/auto-animate、@sapphire/snowflake、katex、mathlive等未使用依赖

apps/admin/package.json

@@ -25,7 +25,6 @@
   },
   "dependencies": {
     "@better-scroll/core": "2.5.1",
-    "@formkit/auto-animate": "^0.9.0",
     "@iconify/vue": "5.0.0",
     "@opentiny/fluent-editor": "^4.0.1",
     "@sa/axios": "workspace:*",
@@ -33,17 +32,13 @@
     "@sa/hooks": "workspace:*",
     "@sa/materials": "workspace:*",
     "@sa/utils": "workspace:*",
-    "@sapphire/snowflake": "^3.5.5",
     "@vueuse/core": "14.1.0",
-    "@zumer/snapdom": "^2.0.1",
     "ali-oss": "^6.23.0",
     "clipboard": "2.0.11",
     "dayjs": "1.11.19",
     "defu": "6.1.4",
     "echarts": "6.0.0",
     "json5": "2.2.3",
-    "katex": "^0.16.27",
-    "mathlive": "^0.108.2",
     "naive-ui": "2.43.2",
     "nprogress": "0.2.0",
     "path-browserify": "^1.0.1",