refactor: 移除java项目，改用hono + vercel function实现后端 (#1)

Co-authored-by: gin <gin-18@qq.com>
Co-authored-by: gin <dengxinmin@owlscm.com>
Reviewed-on: #1

backend/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "types": ["node"],
+    "outDir": "dist"
+  },
+  "include": ["src/**/*.ts"]
+}