feat: implement US-2 - create print route with barcode data fetching

- Add Next.js print route at /[locale]/print/[year]/[month]
- Implement fetchBarcodeDataForPrint function with user authentication
- Create PrintPreview component with basic table layout
- Add proper 404 handling with not-found.tsx
- Fix barcode image display with flexible data URL handling
- Filter and sort bills with barcode data for consistent display

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

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

app/[locale]/print/[year]/[month]/not-found.tsx

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+import { NotFoundPage } from '@/app/ui/NotFoundPage';
+
+const PrintPageNotFound = () =>
+<NotFoundPage title="404 Print Page Not Found" description="Could not find the requested print preview page." />;
+
+export default PrintPageNotFound;

app/[locale]/print/[year]/[month]/page.tsx

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+import { fetchBarcodeDataForPrint } from '@/app/lib/actions/printActions';
+import { notFound } from 'next/navigation';
+import { PrintPreview } from '@/app/ui/PrintPreview';
+
+interface PrintPageProps {
+  params: { 
+    year: string; 
+    month: string; 
+    locale: string;
+  };
+}
+
+export default async function PrintPage({ params }: PrintPageProps) {
+  const year = parseInt(params.year);
+  const month = parseInt(params.month);
+
+  // Validate year and month parameters
+  if (isNaN(year) || isNaN(month) || month < 1 || month > 12) {
+    notFound();
+  }
+
+  let printData;
+  
+  try {
+    printData = await fetchBarcodeDataForPrint(year, month);
+  } catch (error) {
+    console.error('Error fetching print data:', error);
+    notFound();
+  }
+
+  // If no barcode data found, show empty state
+  if (!printData || printData.length === 0) {
+    return (
+      <div className="min-h-screen flex items-center justify-center">
+        <div className="text-center">
+          <h1 className="text-2xl font-bold mb-4">No Barcode Data Found</h1>
+          <p className="text-gray-600">
+            No bills with 2D barcodes found for {year}-{month.toString().padStart(2, '0')}
+          </p>
+        </div>
+      </div>
+    );
+  }
+
+  return <PrintPreview data={printData} year={year} month={month} />;
+}

app/lib/actions/printActions.ts

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+'use server';
+
+import { getDbClient } from '../dbClient';
+import { BillingLocation, Bill } from '../db-types';
+import { AuthenticatedUser } from '../types/next-auth';
+import { withUser } from '../auth';
+import { unstable_noStore as noStore } from 'next/cache';
+
+export interface PrintBarcodeData {
+  locationName: string;
+  billName: string;
+  barcodeImage: string;
+  yearMonth: string;
+}
+
+/**
+ * Fetches all bills with barcode images for a specific month for printing
+ * @param year - Year to fetch data for
+ * @param month - Month to fetch data for (1-12)
+ * @returns Array of barcode data for printing
+ */
+export const fetchBarcodeDataForPrint = withUser(async (user: AuthenticatedUser, year: number, month: number): Promise<PrintBarcodeData[]> => {
+    noStore();
+    
+    const { id: userId } = user;
+    const dbClient = await getDbClient();
+
+    const yearMonth = `${year}-${month.toString().padStart(2, '0')}`;
+
+    // Fetch all locations for the specific month
+    const locations = await dbClient.collection<BillingLocation>("lokacije")
+        .find({
+            userId, // ensure data belongs to authenticated user
+            "yearMonth.year": year,
+            "yearMonth.month": month
+        })
+        .toArray();
+
+    // Extract and flatten barcode data
+    const printData: PrintBarcodeData[] = [];
+    
+    for (const location of locations) {
+        for (const bill of location.bills) {
+            if (bill.barcodeImage && bill.barcodeImage.trim() !== "") {
+                printData.push({
+                    locationName: location.name,
+                    billName: bill.name,
+                    barcodeImage: bill.barcodeImage,
+                    yearMonth: yearMonth
+                });
+            }
+        }
+    }
+
+    // Sort by location name, then by bill name for consistent ordering
+    printData.sort((a, b) => {
+        if (a.locationName !== b.locationName) {
+            return a.locationName.localeCompare(b.locationName);
+        }
+        return a.billName.localeCompare(b.billName);
+    });
+
+    return printData;
+});

app/ui/PrintPreview.tsx

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+'use client';
+
+import { PrintBarcodeData } from '../lib/actions/printActions';
+
+export interface PrintPreviewProps {
+  data: PrintBarcodeData[];
+  year: number;
+  month: number;
+}
+
+export const PrintPreview: React.FC<PrintPreviewProps> = ({ data, year, month }) => {
+  return (
+    <div className="min-h-screen p-4">
+      <h1 className="text-2xl font-bold mb-4">
+        Print Preview - {year}-{month.toString().padStart(2, '0')}
+      </h1>
+      
+      <div className="mb-4">
+        <p>Found {data.length} barcode(s) for printing</p>
+      </div>
+
+      {/* Basic table structure - will be enhanced in US-3 */}
+      <table className="w-full border-collapse border border-gray-300">
+        <thead>
+          <tr>
+            <th className="border border-gray-300 p-2">Index</th>
+            <th className="border border-gray-300 p-2">Bill Info</th>
+            <th className="border border-gray-300 p-2">Barcode</th>
+          </tr>
+        </thead>
+        <tbody>
+          {data.map((item, index) => (
+            <tr key={`${item.locationName}-${item.billName}`}>
+              <td className="border border-gray-300 p-2">{index + 1}</td>
+              <td className="border border-gray-300 p-2">
+                <div>
+                  <div className="font-medium">{item.yearMonth}</div>
+                  <div>{item.locationName}</div>
+                  <div>{item.billName}</div>
+                </div>
+              </td>
+              <td className="border border-gray-300 p-2">
+                <img 
+                  src={item.barcodeImage.startsWith('data:') ? item.barcodeImage : `data:image/png;base64,${item.barcodeImage}`} 
+                  alt={`Barcode for ${item.billName}`}
+                  className="max-w-full h-auto"
+                />
+              </td>
+            </tr>
+          ))}
+        </tbody>
+      </table>
+      
+      {/* Print button - will be enhanced in US-4 */}
+      <button 
+        onClick={() => window.print()} 
+        className="mt-4 px-4 py-2 bg-blue-500 text-white rounded hover:bg-blue-600"
+      >
+        Print
+      </button>
+    </div>
+  );
+};