fix: DB Pool 5→20 + KPI/Charts Skip DB-Load

Pool-Size von 5 auf 20 erhöht (Connection-Exhaustion bei
parallelen Finanzplan-Queries + Compute + API-Calls)

KPIs/Charts Tabs laden keine DB-Daten (virtual tabs,
Daten sind hardcoded) → sofortiges Rendering

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

pitch-deck/components/slides/FinanzplanSlide.tsx

@@ -75,6 +75,11 @@ export default function FinanzplanSlide({ lang }: FinanzplanSlideProps) {
 
   // Load sheet data
   const loadSheet = useCallback(async (name: string) => {
+    if (name === 'kpis' || name === 'charts') {
+      setRows([])
+      setLoading(false)
+      return
+    }
     setLoading(true)
     try {
       const r = await fetch(`/api/finanzplan/${name}`)