fix(billing): Prevent crash on invalid data category for plan

The getBucket function would throw an error when it couldn't find a
valid bucket for a data category, causing the billing overview page
to crash. Now it reports the error to Sentry with full context but
returns a fallback bucket with zero price, allowing the page to
continue rendering.

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

Author: volokluev

static/gsApp/views/amCheckout/utils.tsx

@@ -185,7 +185,23 @@ export function getBucket({
       return buckets[slot]!;
     }
   }
-  throw new Error('Invalid data category for plan');
+
+  // Report to Sentry but don't crash the page
+  Sentry.withScope(scope => {
+    scope.setExtras({
+      buckets,
+      events,
+      price,
+      shouldMinimize,
+    });
+    Sentry.captureException(new Error('Invalid data category for plan'));
+  });
+
+  // Return a fallback bucket with zero price to prevent crashes
+  return {
+    price: 0,
+    quantity: events ?? 0,
+  };
 }
 
 type ReservedTotalProps = {