frontend: lab dashboard with add-result flow

New /lab department home: the lab's task queue (tasks assigned to the Lab
department, with done toggle) and an "Add result" dialog — pick a patient,
enter test/value/flag/date — that posts to the new labs append endpoint via
appendLabs() in lib/patients.ts.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/app/(app)/lab/page.tsx

@@ -0,0 +1,10 @@
+import { LabView } from "@/components/lab/lab-view";
+import { SidebarInset } from "@/components/ui/sidebar";
+
+export default function LabPage() {
+  return (
+    <SidebarInset className="flex flex-1 flex-col overflow-y-auto">
+      <LabView />
+    </SidebarInset>
+  );
+}