Production upgrade: Clerk auth, Stripe billing, analytics, PWA support

Backend & Auth:
- Add @clerk/nextjs for production authentication
- Create src/proxy.ts with clerkMiddleware() for route protection
- Implement multi-tenant auth with role-based access control
- Add Clerk components (Show, UserButton, SignInButton, SignUpButton)

Billing & Payments:
- Full Stripe integration (subscriptions, add-ons, customer portal)
- Plan tiers: Starter 9/mo, Farm 49/mo, Enterprise 99/mo
- Webhook handling for subscription events
- createSubscription(), createAddonSubscription(), createCustomerPortalSession()

API & Security:
- Rate limiting with @upstash/ratelimit (100 req/min API, 20 req/min checkout)
- Zod validation schemas for all endpoints (orders, products, campaigns, etc.)
- Security headers (CSP, HSTS, X-Frame-Options)
- API routes: /api/v1/ with validated, rate-limited endpoints

Monitoring:
- Sentry error tracking with performance monitoring
- PostHog analytics for feature usage, funnels, cohorts
- User activity logging and breadcrumb tracking

Admin Features:
- Analytics dashboard with revenue charts, customer growth, conversion funnel
- Onboarding flow with 6-step interactive tour
- Referral system with share tracking and reward redemption
- Changelog feed with in-app notifications

PWA & SEO:
- Web app manifest with icons and shortcuts
- Service worker for offline support and caching
- Full SEO metadata, OpenGraph, Twitter cards
- Structured data (JSON-LD) for organization and products

Database:
- Add referral_codes, changelogs, onboarding_progress tables
- Add user_activity_logs, api_keys, notification_preferences
- Comprehensive RLS policies for all new tables
- Seed data for demo brands and products

src/lib/sentry.ts

@@ -0,0 +1,75 @@
+// Sentry configuration for production error monitoring
+import * as Sentry from "@sentry/nextjs";
+
+Sentry.init({
+  dsn: process.env.SENTRY_DSN,
+  
+  // Performance monitoring
+  tracesSampleRate: process.env.NODE_ENV === "production" ? 0.1 : 1.0,
+  
+  // Environment
+  environment: process.env.NODE_ENV,
+  
+  // Release tracking
+  release: process.env.GIT_SHA || process.env.VERCEL_GIT_COMMIT_SHA,
+  
+  // Error sampling - capture more errors in production
+  sampleRate: 1.0,
+  
+  // Replay sessions for debugging
+  replaysSessionSampleRate: process.env.NODE_ENV === "production" ? 0.05 : 0,
+  replaysOnErrorSampleRate: 0.5,
+  
+  // Ignore common non-actionable errors
+  ignoreErrors: [
+    "ResizeObserver loop",
+    "Non-Error promise rejection captured",
+    "The operation was aborted",
+  ],
+  
+  // Tags for filtering in Sentry dashboard
+  initialScope: {
+    tags: {
+      source: "route-commerce",
+    },
+  },
+  
+  // BeforeSend hook for data sanitization
+  beforeSend(event) {
+    // Remove any PII or sensitive data before sending
+    if (event.user) {
+      delete event.user.ip;
+      delete event.user.email;
+    }
+    return event;
+  },
+});
+
+// Export for manual error capture
+export const captureError = (error: Error, context?: Record<string, unknown>) => {
+  Sentry.captureException(error, {
+    extra: context,
+  });
+};
+
+// Export for manual breadcrumb logging
+export const addBreadcrumb = (message: string, data?: Record<string, unknown>) => {
+  Sentry.addBreadcrumb({
+    message,
+    data,
+    timestamp: Date.now() / 1000,
+  });
+};
+
+// Export for user tracking during errors
+export const setUserContext = (userId: string, brandId?: string) => {
+  Sentry.setUser({
+    id: userId,
+    tags: { brand_id: brandId || "unknown" },
+  });
+};
+
+// Export for transaction tracing
+export const startTransaction = (name: string, op: string = "custom") => {
+  return Sentry.startTransaction({ name, op });
+};