perf(desktop): lazy-load renderer routes and pause polling when hidden

Drop the eager Antd global import in favour of unplugin-vue-components
on-demand resolution, async route components, defineAsyncComponent for
the shell/login split, and a dynamic Modal import inside
showClientActionError. Pair that with a visibility-aware runtime poller
that stops the 15s snapshot refresh when the window is hidden and kicks
off an immediate refresh on re-show. Refresh DesktopShell nav with
inline icons and a calmer active/hover treatment, and land
ActionButton/DisclosurePanel/PaginationBar primitives for upcoming
views.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop-client/src/renderer/App.vue

@@ -1,9 +1,9 @@
 <script setup lang="ts">
-import { onMounted } from "vue";
-
-import DesktopShell from "./components/DesktopShell.vue";
+import { defineAsyncComponent, onMounted } from "vue";
 import { useDesktopSession } from "./composables/useDesktopSession";
-import LoginView from "./views/LoginView.vue";
+
+const DesktopShell = defineAsyncComponent(() => import("./components/DesktopShell.vue"));
+const LoginView = defineAsyncComponent(() => import("./views/LoginView.vue"));
 
 const { isAuthenticated, syncRuntimeSession } = useDesktopSession();