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

src/components/onboarding/OnboardingFlow.tsx

@@ -87,7 +87,7 @@ interface OnboardingProps {
   onComplete?: () => void;
 }
 
-export function OnboardingFlow({ brandId, userId, onComplete }: OnboardingProps) {
+export function OnboardingFlow({ brandId: _brandId, userId: _userId, onComplete }: OnboardingProps) {
   const [currentStep, setCurrentStep] = useState(0);
   const [isCompleted, setIsCompleted] = useState(false);
   const router = useRouter();
@@ -151,7 +151,7 @@ export function OnboardingFlow({ brandId, userId, onComplete }: OnboardingProps)
           </div>
           <h2 className="text-2xl font-bold text-gray-900 mb-2">Setup Complete!</h2>
           <p className="text-gray-600 mb-6">
-            You're ready to start growing your wholesale business.
+            You&apos;re ready to start growing your wholesale business.
           </p>
           <button
             onClick={() => router.push("/admin")}