fix(pitch-deck): add grossMargin + nrr to FinanzplanSlide KPIs

Charts tab showed 0 for Gross Margin and NRR because these fields
were not computed in the FinanzplanSlide's own fpKPIs loading
(only existed in the useFpKPIs shared hook).

Added: grossMargin = (revenue - material) / revenue × 100
Added: nrr = revenue / prevYearRevenue × 100

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

pitch-deck/components/slides/FinanzplanSlide.tsx

@@ -148,8 +148,12 @@ export default function FinanzplanSlide({ lang, investorId, preferredScenarioId,
           const revPerEmp = headcount > 0 ? Math.round(revenue / headcount) : 0
           const ebitMargin = revenue > 0 ? Math.round((ebit / revenue) * 100) : 0
           const burnRate = liquiditaet < 0 ? Math.round(Math.abs(ebit / 12)) : 0
+          const material = findGuv('Summe Materialaufwand')?.values?.[yk] || 0
+          const grossMargin = revenue > 0 ? Math.round(((revenue - material) / revenue) * 100) : 0
+          const prevRevenue = y > 2026 ? (findGuv('Umsatzerlöse')?.values?.[`y${y - 1}`] || 0) : 0
+          const nrr = prevRevenue > 0 ? Math.round((revenue / prevRevenue) * 100) : 0
 
-          kpis[yk] = { revenue, ebit, personal, netIncome, steuern, liquiditaet, customers, headcount, mrr, arr, arpu, revPerEmp, ebitMargin, burnRate }
+          kpis[yk] = { revenue, ebit, personal, netIncome, steuern, liquiditaet, customers, headcount, mrr, arr, arpu, revPerEmp, ebitMargin, burnRate, grossMargin, nrr }
         }
         setFpKPIs(kpis)
       } catch { /* ignore */ }