chore: remove prototype files and unused UI assets

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/components/layout/SidebarRail.vue

@@ -9,7 +9,7 @@
       </div>
       <strong class="brand-name">星海科技</strong>
       <button class="brand-toggle" type="button" aria-label="打开 AI 助手" @click="emit('openChat')">
-        <i class="pi pi-angle-double-left"></i>
+        <i class="mdi mdi-chevron-double-left"></i>
       </button>
     </div>
 
@@ -34,7 +34,7 @@
         <strong>张晓明</strong>
         <span>财务管理员</span>
       </span>
-      <i class="pi pi-angle-down"></i>
+      <i class="mdi mdi-chevron-down"></i>
     </button>
   </aside>
 </template>
@@ -52,8 +52,9 @@ const emit = defineEmits(['navigate', 'openChat'])
 const sidebarMeta = {
   overview: { label: '总览' },
   requests: { label: '差旅申请/报销' },
+  approval: { label: '审批中心', badge: '12' },
   chat: { label: 'AI助手' },
-  policies: { label: '政策规则' },
+  policies: { label: '知识管理' },
   audit: { label: '审计追踪' }
 }
 
@@ -278,7 +279,7 @@ const decoratedNavItems = computed(() =>
   text-overflow: ellipsis;
 }
 
-.rail-user .pi {
+.rail-user .mdi {
   justify-self: end;
   color: #718096;
   font-size: 13px;