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/pages/InfrastructurePage.tsx

@@ -1,6 +1,7 @@
-import { useState } from 'react';
+import { useState, useMemo } from 'react';
 import { Plus, Server, MapPin, Zap, HardDrive, Wrench, ChevronDown, ChevronUp, Thermometer, Shield, X } from 'lucide-react';
 import { useGameStore } from '@/store';
+import { useShallow } from 'zustand/shallow';
 import {
   formatMoney, formatNumber, formatPercent,
   LOCATION_CONFIGS, DC_TIER_CONFIGS, RACK_SKU_CONFIGS,
@@ -105,7 +106,7 @@ function CapacityBar({ label, used, max, unit, icon: Icon }: {
 
 function DataCenterCard({ dcId }: { dcId: string }) {
   const dc = useGameStore((s) => s.infrastructure.dataCenters.find(d => d.id === dcId))!;
-  const pipelineForDc = useGameStore((s) => s.infrastructure.rackPipeline.filter(o => o.dataCenterId === dcId));
+  const pipelineForDc = useGameStore(useShallow((s) => s.infrastructure.rackPipeline.filter(o => o.dataCenterId === dcId)));
   const money = useGameStore((s) => s.economy.money);
   const era = useGameStore((s) => s.meta.currentEra);
   const completedResearch = useGameStore((s) => s.research.completedResearch);