feat: 初始化 Nest 服务骨架与多平台 Chat SSE 网关

- 新增 NestJS + Fastify 入口、配置模块与 Swagger 集成
- 划分 client-app / admin-app 与 shared-domain ai-gateway
- 实现统一 SSE Chat 接口，支持千问、DeepSeek、火山引擎非流式上游与网关分片输出
- 补充项目方案与 JWT 最小实现文档

Made-with: Cursor

tsconfig.json

@@ -0,0 +1,34 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "declaration": false,
+    "removeComments": true,
+    "emitDecoratorMetadata": true,
+    "experimentalDecorators": true,
+    "allowSyntheticDefaultImports": true,
+    "target": "ES2021",
+    "rootDir": "./src",
+    "sourceMap": true,
+    "outDir": "./dist",
+    "baseUrl": "./",
+    "incremental": true,
+    "strict": true,
+    "noImplicitAny": false,
+    "strictNullChecks": true,
+    "moduleResolution": "node",
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "types": ["node"],
+    "paths": {
+      "@common/*": ["src/common/*"],
+      "@config/*": ["src/config/*"],
+      "@apps/*": ["src/apps/*"],
+      "@shared/*": ["src/apps/shared-domain/*"],
+      "@prisma/*": ["src/prisma/*"]
+    },
+    "ignoreDeprecations": "6.0"
+  },
+  "include": ["src/**/*", "prisma/**/*"],
+  "exclude": ["node_modules", "dist"]
+}
+