Update how user data is displayed and searched for

Modify the Avoir interface to make invoiceReference and amount optional. Adjust the filtering logic in Avoirs.tsx to safely handle potentially undefined invoiceReference values.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 9fcf4b21-eb0c-4e53-a567-e2ce4a6ad869
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/9fcf4b21-eb0c-4e53-a567-e2ce4a6ad869/QDWg25A

client/src/pages/Avoirs.tsx

@@ -24,8 +24,8 @@ interface Avoir {
   id: number;
   supplierId: number;
   groupId: number;
-  invoiceReference: string;
-  amount: number;
+  invoiceReference?: string;
+  amount?: number;
   comment?: string;
   commercialProcessed: boolean;
   status: 'En attente de demande' | 'Demandé' | 'Reçu';
@@ -161,7 +161,7 @@ export default function Avoirs() {
 
   // Filter avoirs based on search term
   const filteredAvoirs = avoirs.filter(avoir =>
-    avoir.invoiceReference.toLowerCase().includes(searchTerm.toLowerCase()) ||
+    avoir.invoiceReference?.toLowerCase().includes(searchTerm.toLowerCase()) ||
     avoir.supplier.name.toLowerCase().includes(searchTerm.toLowerCase()) ||
     avoir.comment?.toLowerCase().includes(searchTerm.toLowerCase()) ||
     (avoir.creator.firstName && avoir.creator.lastName