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/src/views/PersonalWorkbenchView.vue

@@ -0,0 +1,9 @@
+<template>
+  <PersonalWorkbench :show-header="false" @open-assistant="emit('openAssistant', $event)" />
+</template>
+
+<script setup>
+import PersonalWorkbench from '../components/business/PersonalWorkbench.vue'
+
+const emit = defineEmits(['openAssistant'])
+</script>