Fix max update depth crash on Infrastructure page

ToastContainer's useEffect had `seen` (a Set state) in its dependency
array — each setSeen created a new Set, re-fired the effect, and under
rapid notifications cascaded past React's 50-update limit. Replaced
with a ref since seen doesn't need to trigger re-renders.

Also added useShallow to DataCenterCard's pipeline selector to prevent
.filter() from causing spurious re-renders on unrelated store changes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/components/common/ToastContainer.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useState } from 'react';
+import { useEffect, useState, useRef } from 'react';
 import { X, CheckCircle, AlertTriangle, Info, AlertCircle } from 'lucide-react';
 import { useGameStore, type GameNotification } from '@/store';
 
@@ -10,23 +10,19 @@ export function ToastContainer() {
   const notifications = useGameStore((s) => s.notifications);
   const dismissNotification = useGameStore((s) => s.dismissNotification);
   const [toasts, setToasts] = useState<Toast[]>([]);
-  const [seen, setSeen] = useState(new Set<string>());
+  const seenRef = useRef(new Set<string>());
 
   useEffect(() => {
-    const newNotifs = notifications.filter(n => !n.read && !seen.has(n.id));
+    const newNotifs = notifications.filter(n => !n.read && !seenRef.current.has(n.id));
     if (newNotifs.length === 0) return;
 
-    setSeen(prev => {
-      const next = new Set(prev);
-      for (const n of newNotifs) next.add(n.id);
-      return next;
-    });
+    for (const n of newNotifs) seenRef.current.add(n.id);
 
     setToasts(prev => [
       ...newNotifs.map(n => ({ ...n, exiting: false })),
       ...prev,
     ].slice(0, 5));
-  }, [notifications, seen]);
+  }, [notifications]);
 
   useEffect(() => {
     if (toasts.length === 0) return;