Set Up Failed Payment Recovery Emails

I need to set up a dunning system to recover failed subscription payments. Most SaaS products lose 5-10% of revenue to involuntary churn — help me minimize that with Stripe's built-in tools plus custom emails.

Product details:
- Product: [your SaaS name]
- Billing: Stripe subscriptions (monthly and/or annual)
- Current MRR: $[X] (even a rough estimate helps prioritize)
- Email sending: [e.g. "Stripe's built-in emails", "SendGrid", "Resend", "ConvertKit"]
- Frontend framework: [e.g. Next.js, React — for the update payment page]
- Estimated failed payment rate: [e.g. "don't know yet", "about 5%"]

Set up the complete recovery system:

1. Stripe retry settings (Smart Retries):
   - Navigate to: Settings > Billing > Subscriptions and emails > Manage failed payments
   - Enable Smart Retries (Stripe's ML-based retry timing)
   - Configure the retry schedule: recommend the optimal number of retries and timing
   - Set what happens after all retries fail: cancel subscription vs mark as unpaid
   - Explain why Smart Retries outperform fixed-schedule retries

2. Stripe's built-in dunning emails:
   - Enable the 3 default payment failure emails in Stripe Dashboard
   - Customize each email:
     - Email 1 (sent immediately): "Your payment didn't go through"
     - Email 2 (sent after 3 days): "Action needed — update your card"
     - Email 3 (sent after 7 days): "Last chance before your account is paused"
   - For each email, write the subject line and body copy:
     - Tone: helpful and human, not threatening
     - Include a direct link to update payment method
     - Mention what they'll lose access to if not resolved
     - Keep each under 100 words

3. Custom recovery page:
   - Build an "Update your payment method" page at /account/billing or /update-payment
   - Use Stripe's Customer Portal or create a custom form with Stripe Elements
   - Show the customer: what failed, when their access expires, and a form to enter a new card
   - Give me the complete code for this page in [frontend framework]
   - After successful update, redirect to a confirmation page and trigger a "payment_recovered" event

4. Webhook-driven custom emails (if I want more control than Stripe's defaults):
   - Listen for these Stripe webhook events:
     - invoice.payment_failed — send custom failure notification
     - customer.subscription.updated (status: past_due) — send escalation email
     - customer.subscription.deleted — send final "we're sorry to see you go" email
     - invoice.paid (after previously failing) — send "welcome back" confirmation
   - Give me the webhook handler code and email copy for each event

5. In-app notifications:
   - Show a banner at the top of the dashboard when payment is past due
   - Include a one-click link to the Stripe Customer Portal to update their card
   - Give me a React component for this banner with the logic to show/hide it based on subscription status

6. Recovery metrics to track:
   - Percentage of failed payments recovered (target: 50-70%)
   - Average time to recovery
   - Revenue saved per month through dunning
   - Show me where to find these numbers in Stripe Dashboard

Build this so I set it up once and it runs forever. Prioritize the highest-impact steps first in case I run out of time.