feat: implement US-1 - add print button to MonthCard with i18n support

- Add PrintButton component with card styling matching AddLocationButton
- Integrate print button next to "Add a new realestate" with centered layout
- Add English/Croatian translations for print tooltips and labels
- Implement click handler to open print preview in new tab
- Create Sprint Playbook for barcode print functionality

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

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

app/ui/MonthLocationList.tsx

@@ -6,6 +6,7 @@ import { AddMonthButton } from "./AddMonthButton";
 import { MonthCard } from "./MonthCard";
 import Pagination from "./Pagination";
 import { LocationCard } from "./LocationCard";
+import { PrintButton } from "./PrintButton";
 import { BillingLocation, YearMonth } from "../lib/db-types";
 import { useRouter, useSearchParams } from "next/navigation";
 import { ToastContainer } from 'react-toastify';
@@ -83,7 +84,10 @@ export const MonthLocationList:React.FC<MonthLocationListProps  > = ({
                             locations.map((location, ix) => <LocationCard key={`location-${location._id}`} location={location} />)
                             : null
                     }
-                    <AddLocationButton yearMonth={yearMonth} />
+                    <div className="flex gap-2 justify-center">
+                      <AddLocationButton yearMonth={yearMonth} />
+                      <PrintButton yearMonth={yearMonth} />
+                    </div>
                 </MonthCard>
                 )
             }