feat: complete launch & marketing layer

- Add marketing pages: blog, changelog, roadmap, waitlist, security, maintenance
- Add GDPR cookie consent banner with preference modal
- Add referral system with API routes for code generation/tracking
- Add waitlist API with referral support
- Add PWA support: manifest, service worker, install prompt
- Add onboarding flow with 6-step guided tour
- Add in-app notification center with bell dropdown
- Add admin launch checklist (32 items across 8 categories)
- Update landing page with trust badges
- Add Open Graph image and favicon
- Configure ESLint for PWA install patterns
- Add LAUNCH_CHECKLIST.md with go-to-market guide

Supabase migrations for:
- blog_posts and blog_categories tables
- waitlist_signups table
- roadmap_items table
- launch_checklist_items table

package.json

@@ -26,11 +26,13 @@
     "exceljs": "^4.4.0",
     "framer-motion": "^12.40.0",
     "gsap": "^3.15.0",
+    "lucide-react": "^1.17.0",
     "next": "^16.2.6",
     "next-themes": "^0.4.6",
     "openai": "^6.37.0",
     "papaparse": "^5.5.3",
     "pdf-lib": "^1.17.1",
+    "posthog-js": "^1.378.1",
     "posthog-node": "^5.35.11",
     "qrcode": "^1.5.4",
     "react": "19.2.4",