feat: 完成P6-P8前端能力闭环（V3,D2,D3,B3）

client/src/components/navigation/NavLinks.tsx

@@ -26,6 +26,11 @@ export const NAV_ITEMS: NavItem[] = [
     label: "票据中心",
     anyOf: ["invoice.upload", "invoice.view_own", "invoice.manage"],
   },
+  {
+    to: "/budgets",
+    label: "预算管理",
+    anyOf: ["budget.view", "budget.manage"],
+  },
   {
     to: "/audit-logs",
     label: "审计工作台",