feat(pitch-deck): NRR + Payback formula-based from fp_* data

- NRR: Revenue year N / Revenue year N-1 × 100 (no more "target > 120%")
- Payback: CAC / monthly gross profit (no more "target < 3 months")
- Both computed in useFpKPIs hook from fp_guv data
- BusinessModelSlide shows computed values with "(berechnet)" label

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

pitch-deck/components/slides/BusinessModelSlide.tsx

@@ -69,8 +69,8 @@ export default function BusinessModelSlide({ lang, isWandeldarlehen }: BusinessM
   const metrics = [
     { icon: DollarSign, color: 'text-indigo-400', label: 'ACV (2030)', value: acvLabel, sub: de ? 'Durchschnittlicher Vertragswert (berechnet)' : 'Average Contract Value (computed)' },
     { icon: TrendingUp, color: 'text-emerald-400', label: 'Gross Margin', value: `${Math.round(grossMargin)}%`, sub: de ? 'Cloud-native, keine Hardware-Kosten' : 'Cloud-native, no hardware costs' },
-    { icon: Repeat, color: 'text-purple-400', label: 'NRR Ziel', value: '> 120%', sub: de ? 'Upsell: mehr Module, mehr Nutzer' : 'Upsell: more modules, more users' },
-    { icon: Target, color: 'text-amber-400', label: 'Payback', value: de ? '< 3 Monate' : '< 3 Months', sub: de ? 'Ersparnis übersteigt Kosten ab Q1' : 'Savings exceed costs from Q1' },
+    { icon: Repeat, color: 'text-purple-400', label: 'NRR (2030)', value: last?.nrr ? `${last.nrr}%` : '—', sub: de ? 'Umsatzwachstum Bestandskunden (berechnet)' : 'Revenue growth existing customers (computed)' },
+    { icon: Target, color: 'text-amber-400', label: de ? 'Payback (2030)' : 'Payback (2030)', value: last?.paybackMonths ? `${last.paybackMonths} ${de ? 'Mon.' : 'mo.'}` : '—', sub: de ? 'CAC / monatlicher Deckungsbeitrag (berechnet)' : 'CAC / monthly contribution margin (computed)' },
   ]
 
   return (