Add payment schedule view with filtering and supplier payment methods

Adds a new payment schedule page to display due dates and amounts, incorporating supplier payment methods and date filtering.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 1e4433b5-47ab-464c-b663-fea2e53367dd
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Event-Id: e9c65355-546d-41f7-885b-728c905f4497
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/1e4433b5-47ab-464c-b663-fea2e53367dd/9uIte90

client/src/components/Sidebar.tsx

@@ -35,7 +35,8 @@ import {
   FileUp,
   Send,
   Receipt,
-  TrendingUp
+  TrendingUp,
+  CreditCard
 } from "lucide-react";
 
 export default function Sidebar() {
@@ -270,6 +271,12 @@ export default function Sidebar() {
       icon: TrendingUp, 
       roles: ["admin", "directeur"] 
     },
+    { 
+      path: "/payment-schedule", 
+      label: "Échéance", 
+      icon: CreditCard, 
+      roles: ["admin", "directeur"] 
+    },
     { 
       path: "/avoirs", 
       label: "Avoirs",