Debug: Add detailed logging for Royal Mail API calls

- Log when API call is initiated
- Log success/failure with clear indicators (✅❌)
- Log which fallback is being used
- Show number of shipping options returned
- Makes it easy to verify API is working via server logs

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/lib/royalmail-shipping.ts

@@ -47,14 +47,21 @@ export async function getRoyalMailShippingQuotes(
   // Use live Royal Mail API if credentials available
   const apiKey = process.env.ROYAL_MAIL_API_KEY;
   const apiSecret = process.env.ROYAL_MAIL_API_SECRET;
+
   if (apiKey && apiSecret) {
     try {
-      return await fetchRealRoyalMailRates(weightKg, destinationCountry, apiKey, apiSecret);
+      console.log('🚀 Fetching live Royal Mail rates...');
+      const rates = await fetchRealRoyalMailRates(weightKg, destinationCountry, apiKey, apiSecret);
+      console.log('✅ Royal Mail API SUCCESS - Got', rates.length, 'shipping options');
+      return rates;
     } catch (error) {
-      console.warn('Royal Mail API error, falling back to estimated rates:', error);
+      console.error('❌ Royal Mail API FAILED:', error instanceof Error ? error.message : String(error));
+      console.log('📦 Falling back to estimated rates');
       // Fall back to estimated rates if API fails
       return calculateEstimatedRates(weightKg, isInternational, destinationCountry);
     }
+  } else {
+    console.log('⚠️ Royal Mail API credentials not configured - using estimated rates');
   }
 
   // Fallback to estimated rates