feat: Add DevSecOps tools, Woodpecker proxy, Vault persistent storage, pitch-deck annex slides

- Install Gitleaks, Trivy, Grype, Syft, Semgrep, Bandit in backend-core Dockerfile
- Add Woodpecker SQLite proxy API (fallback without API token)
- Mount woodpecker_data volume read-only to backend-core
- Add backend proxy fallback in admin-core Woodpecker route
- Add Vault file-based persistent storage (config.hcl, init-vault.sh)
- Auto-init, unseal and root-token persistence for Vault
- Add 6 pitch-deck annex slides (Assumptions, Architecture, GTM, Regulatory, Engineering, AI Pipeline)
- Dynamic margin/amortization KPIs in BusinessModelSlide
- Market sources modal with citations in MarketSlide
- Redesign nginx landing page to 3-column layout (Lehrer/Compliance/Core)
- Extend MkDocs nav with Services and SDK documentation sections
- Add SDK Protection architecture doc

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pitch-deck/components/SlideContainer.tsx

@@ -42,9 +42,9 @@ export default function SlideContainer({ children, slideKey, direction }: SlideC
           opacity: { duration: 0.3 },
           scale: { duration: 0.3 },
         }}
-        className="absolute inset-0 flex items-center justify-center overflow-y-auto"
+        className="absolute inset-0 flex justify-center overflow-y-auto"
       >
-        <div className="w-full max-w-6xl mx-auto px-6 py-12 md:py-16">
+        <div className="w-full max-w-6xl mx-auto px-6 py-12 md:py-16 my-auto">
           {children}
         </div>
       </motion.div>