feat(pitch-deck): business model redesign + umlauts fix + tab animations

Business Model slide completely rewritten:
- Left: 3 pricing tiers (Starter/Professional/Enterprise)
- Right: Unit Economics (ACV, Gross Margin, NRR, Payback)
- Bottom-up sizing: 1,200 customers × 8,400 ACV = 10M ARR
- Land & Expand arrow visualization

Umlauts: 75+ ae/oe/ue → ä/ö/ü replacements across 10 slide files

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

pitch-deck/components/slides/FinancialsSlide.tsx

@@ -47,7 +47,7 @@ export default function FinancialsSlide({ lang, investorId }: FinancialsSlidePro
   const initialFunding = (fm.activeScenario?.assumptions.find(a => a.key === 'initial_funding')?.value as number) || 200000
 
   const tabs: { id: FinTab; label: string }[] = [
-    { id: 'overview', label: de ? 'Uebersicht' : 'Overview' },
+    { id: 'overview', label: de ? 'Übersicht' : 'Overview' },
     { id: 'guv', label: de ? 'GuV (Jahres)' : 'P&L (Annual)' },
     { id: 'cashflow', label: de ? 'Cashflow & Finanzbedarf' : 'Cashflow & Funding' },
   ]