feat(client): 导航布局收敛与移动端菜单（E3）

- Sidebar/Topbar 统一交互与样式
- 移动端抽屉菜单（Dialog）+ 账号下拉菜单（DropdownMenu）
- 导航项抽取为 NavLinks 便于后续扩展

client/src/components/navigation/NavLinks.tsx

@@ -0,0 +1,70 @@
+import { NavLink } from "react-router-dom";
+import { useAuth } from "../../auth/AuthContext";
+import { hasAnyPermission } from "../../auth/permissions";
+import { cn } from "../../lib/utils";
+
+export type NavItem = {
+  to: string;
+  label: string;
+  anyOf?: string[];
+};
+
+export const NAV_ITEMS: NavItem[] = [
+  { to: "/dashboard", label: "仪表盘" },
+  {
+    to: "/reimbursements",
+    label: "我的报销",
+    anyOf: ["expense.view_own", "expense.view_all"],
+  },
+  {
+    to: "/workflow/tasks",
+    label: "待我处理",
+    anyOf: ["expense.approve"],
+  },
+  {
+    to: "/invoice-pool",
+    label: "票据中心",
+    anyOf: ["invoice.upload", "invoice.view_own", "invoice.manage"],
+  },
+  {
+    to: "/audit-logs",
+    label: "审计工作台",
+    anyOf: ["system.audit.view"],
+  },
+  { to: "/settings/profile", label: "个人设置" },
+];
+
+export function NavLinks({ onNavigate }: { onNavigate?: () => void }) {
+  const { permissions } = useAuth();
+
+  const visibleItems = NAV_ITEMS.filter((item) => {
+    if (!item.anyOf) {
+      return true;
+    }
+
+    return hasAnyPermission(permissions, item.anyOf);
+  });
+
+  return (
+    <nav className="space-y-1">
+      {visibleItems.map((item) => (
+        <NavLink
+          key={item.to}
+          to={item.to}
+          onClick={() => onNavigate?.()}
+          className={({ isActive }) =>
+            cn(
+              "block rounded-lg px-3 py-2.5 text-sm font-medium transition-colors",
+              isActive
+                ? "bg-primary-50 text-primary"
+                : "text-slate-700 hover:bg-slate-50 hover:text-slate-900",
+            )
+          }
+        >
+          {item.label}
+        </NavLink>
+      ))}
+    </nav>
+  );
+}
+