fix(pitch-deck): SolutionSlide crash + CompetitionSlide cleanup

- Fix ReferenceError on slide 5: add missing `const de = lang === 'de'`
- Remove feature matrix rows: Hardware Moat, 380+ Regularien, Self-Hosted, Multi-Framework Consent SDK
- Rename IPFS → IPFS/Blockchain (optional)
- Remove Pricing-Einordnung cards and Top 5 Unterschiede accordion

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

pitch-deck/components/slides/SolutionSlide.tsx

@@ -18,6 +18,7 @@ const colors = ['from-blue-500 to-cyan-500', 'from-indigo-500 to-purple-500', 'f
 
 export default function SolutionSlide({ lang }: SolutionSlideProps) {
   const i = t(lang)
+  const de = lang === 'de'
 
   return (
     <div>