feat(web): add Mission Control page layout shell

apps/web/src/components/mission-control/OrchestratorPanel.tsx

@@ -0,0 +1,16 @@
+"use client";
+
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+
+export function OrchestratorPanel(): React.JSX.Element {
+  return (
+    <Card className="flex h-full min-h-[220px] flex-col">
+      <CardHeader>
+        <CardTitle className="text-base">Orchestrator Panel</CardTitle>
+      </CardHeader>
+      <CardContent className="flex flex-1 items-center justify-center text-sm text-muted-foreground">
+        Select an agent
+      </CardContent>
+    </Card>
+  );
+}