docs: 添加中文文档，新增前端和后端代码

- 新增 README_CN.md 中文文档
- 新增 frontend/ Vue 3 前端项目
- 新增 web/ FastAPI 后端项目

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/package.json

@@ -0,0 +1,54 @@
+{
+  "name": "bttoxin_webserver",
+  "packageManager": "pnpm@10.26.1",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "engines": {
+    "node": "^20.19.0 || >=22.12.0"
+  },
+  "scripts": {
+    "dev": "vite",
+    "build": "run-p type-check \"build-only {@}\" --",
+    "preview": "vite preview",
+    "test:unit": "vitest",
+    "build-only": "vite build",
+    "type-check": "vue-tsc --build",
+    "lint": "eslint . --fix --cache",
+    "format": "prettier --write --experimental-cli src/"
+  },
+  "dependencies": {
+    "@element-plus/icons-vue": "^2.3.2",
+    "@motiadev/stream-client-browser": "0.17.9-beta.191",
+    "axios": "^1.13.2",
+    "element-plus": "^2.13.0",
+    "pinia": "^3.0.4",
+    "vue": "^3.5.25",
+    "vue-router": "^4.6.3"
+  },
+  "devDependencies": {
+    "@tsconfig/node24": "^24.0.3",
+    "@types/jsdom": "^27.0.0",
+    "@types/node": "^24.10.1",
+    "@vitejs/plugin-vue": "^6.0.2",
+    "@vitest/eslint-plugin": "^1.5.0",
+    "@vue/eslint-config-prettier": "^10.2.0",
+    "@vue/eslint-config-typescript": "^14.6.0",
+    "@vue/test-utils": "^2.4.6",
+    "@vue/tsconfig": "^0.8.1",
+    "eslint": "^9.39.1",
+    "eslint-plugin-vue": "~10.5.1",
+    "fast-check": "^4.5.2",
+    "jiti": "^2.6.1",
+    "jsdom": "^27.2.0",
+    "npm-run-all2": "^8.0.4",
+    "prettier": "3.6.2",
+    "typescript": "~5.9.0",
+    "unplugin-auto-import": "^20.3.0",
+    "unplugin-vue-components": "^30.0.0",
+    "vite": "^7.2.4",
+    "vite-plugin-vue-devtools": "^8.0.5",
+    "vitest": "^4.0.14",
+    "vue-tsc": "^3.1.5"
+  }
+}