Fix service worker cache preventing code updates and change fallback URL

- Bumped service worker cache version to v2 to force cache invalidation
- Added activate event to explicitly clear old caches
- Enhanced service worker logging with update checking
- Changed API fallback URL from localhost:3001 to https://puffinoffset.com/api

This fixes the issue where new code deployments were not being used due to
service worker caching the old JavaScript with the timing bug.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

public/sw.js

@@ -1,4 +1,4 @@
-const CACHE_NAME = 'puffin-calculator-v1';
+const CACHE_NAME = 'puffin-calculator-v2'; // Bumped to clear old cached code
 const urlsToCache = [
   '/',
   '/mobile-app',
@@ -21,6 +21,22 @@ self.addEventListener('install', (event) => {
   );
 });
 
+// Activate event - clear old caches
+self.addEventListener('activate', (event) => {
+  event.waitUntil(
+    caches.keys().then((cacheNames) => {
+      return Promise.all(
+        cacheNames.map((cacheName) => {
+          if (cacheName !== CACHE_NAME) {
+            console.log('Clearing old cache:', cacheName);
+            return caches.delete(cacheName);
+          }
+        })
+      );
+    })
+  );
+});
+
 // Fetch event - serve from cache when offline
 self.addEventListener('fetch', (event) => {
   event.respondWith(

src/api/checkoutClient.ts

@@ -10,8 +10,8 @@ const getApiBaseUrl = (): string => {
     return window.env.API_BASE_URL;
   }
 
-  // Fall back to build-time env or default
-  return import.meta.env.VITE_API_BASE_URL || 'http://localhost:3001';
+  // Fall back to build-time env or production default
+  return import.meta.env.VITE_API_BASE_URL || 'https://puffinoffset.com/api';
 };
 
 export interface CreateCheckoutSessionParams {

src/main.tsx

@@ -9,10 +9,18 @@ if ('serviceWorker' in navigator) {
   window.addEventListener('load', () => {
     navigator.serviceWorker.register('/sw.js')
       .then((registration) => {
-        console.log('SW registered: ', registration);
+        console.log('✅ Service Worker registered:', registration);
+
+        // Check for updates immediately
+        registration.update();
+
+        // Log when a new service worker is waiting
+        if (registration.waiting) {
+          console.log('⚠️  New service worker waiting. Reload page to activate.');
+        }
       })
       .catch((registrationError) => {
-        console.log('SW registration failed: ', registrationError);
+        console.error('❌ SW registration failed:', registrationError);
       });
   });
 }