feat: implement Story 2.2 — Priority Alerts Panel with UI fixes

Add PriorityAlertsPanel component to the dashboard, update DashboardController
with alert logic, and apply misc UI fixes across sidebar, forms, and pages.
Includes epic-1 retrospective and sprint status update.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

resources/js/pages/client/Upload.vue

@@ -29,7 +29,7 @@ type Props = {
     csrfToken: string;
 };
 
-const props = defineProps<Props>();
+defineProps<Props>();
 
 const page = usePage<{ flash?: { type?: string; message?: string } }>();
 const flash = computed(() => page.props.flash);