Create Subscription Pricing with Two Tiers

Build a /pricing page with two monthly subscription tiers: Starter at $19/month and Pro at $49/month. Each tier should display the plan name, price, and a list of 4-5 features, with a "Get started" CTA button. Wire each button to a serverless function that creates a Stripe Checkout Session using the corresponding Stripe price ID (pass the plan name as metadata). After a successful payment, Stripe should redirect to /onboarding?plan=starter or /onboarding?plan=pro. On success, update the user's subscription_tier column in the database to match the purchased plan, set subscription_status to "active", and store the Stripe customer_id. On the /account/settings page, show the user's current plan name and the next renewal date pulled from the database.