refactor: split project into web and server directories

- Move frontend to web/ directory
- Add server/ directory for backend
- Restructure project for前后端分离架构

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "x-financial-reimbursement-admin",
+  "private": true,
+  "version": "0.1.0",
+  "type": "module",
+  "scripts": {
+    "start": "vite --host 127.0.0.1",
+    "dev": "vite --host 127.0.0.1",
+    "build": "vite build",
+    "preview": "vite preview --host 127.0.0.1"
+  },
+  "dependencies": {
+    "@primevue/themes": "^4.5.4",
+    "@vitejs/plugin-vue": "^5.2.4",
+    "@vueuse/motion": "^3.0.3",
+    "chart.js": "^4.5.1",
+    "primeicons": "^7.0.0",
+    "primevue": "^4.5.5",
+    "vite": "^5.4.19",
+    "vue": "^3.5.13",
+    "vue-chartjs": "^5.3.3"
+  }
+}