Add standards legend to calculator page

- Import and integrate StandardsLegend component
- Place below calculator form as expandable dropdown
- Provides education on Wren's certification standards before checkout

components/CalculatorClient.tsx

@@ -4,6 +4,7 @@ import { useState } from 'react';
 import { TripCalculator } from '../src/components/TripCalculator';
 import { QRCalculatorLoader } from '../src/components/QRCalculatorLoader';
 import { OffsetOrder } from '../src/components/OffsetOrder';
+import { StandardsLegend } from './StandardsLegend';
 import { useHasQRData } from '../src/hooks/useQRDecoder';
 import type { VesselData } from '../src/types';
 
@@ -73,6 +74,11 @@ export function CalculatorClient() {
             onOffsetClick={handleOffsetClick}
           />
         )}
+
+        {/* Standards Legend - Learn about Wren's offset standards */}
+        <div className="w-full">
+          <StandardsLegend />
+        </div>
       </div>
     </div>
   );