fix(pitch-deck): Umlaute in RiskSlide + Sidebar-Name für Risiken

- Alle ä/ö/ü in RiskSlide.tsx korrigiert
- slideNames in i18n.ts: 'Risiken & Mitigation' (DE) + 'Risks & Mitigation' (EN) hinzugefügt

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

pitch-deck/lib/i18n.ts

@@ -37,6 +37,7 @@ const translations = {
       'Anhang: Strategie',
       'Anhang: Finanzplan',
       'Glossar',
+      'Risiken & Mitigation',
       'Rechtlicher Hinweis',
     ],
     executiveSummary: {
@@ -334,6 +335,7 @@ const translations = {
       'Appendix: Strategy',
       'Appendix: Financial Plan',
       'Glossary',
+      'Risks & Mitigation',
       'Legal Notice',
     ],
     executiveSummary: {