feat: add duplicate transaction detection and display in transactions page, enhancing user experience with visual indicators for duplicates

app/api/banking/duplicates/ids/route.ts

@@ -0,0 +1,20 @@
+import { NextResponse } from "next/server";
+import { transactionService } from "@/services/transaction.service";
+import { requireAuth } from "@/lib/auth-utils";
+
+export async function GET() {
+  const authError = await requireAuth();
+  if (authError) return authError;
+
+  try {
+    const duplicateIds = await transactionService.getDuplicateIds();
+    return NextResponse.json({ duplicateIds: Array.from(duplicateIds) });
+  } catch (error) {
+    console.error("Error finding duplicate IDs:", error);
+    return NextResponse.json(
+      { error: "Failed to find duplicate IDs" },
+      { status: 500 },
+    );
+  }
+}
+