Update webhook request to use POST method with JSON payload

Modify the webhook integration to send data via POST request with a JSON payload, resolving a "400 Request Header Or Cookie Too Large" error caused by excessive custom headers.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: cfbfe47c-0c9a-4ebf-8a41-2937407eccff
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/cfbfe47c-0c9a-4ebf-8a41-2937407eccff/7RlGXpp

server/routes.ts

@@ -149,17 +149,14 @@ export async function registerRoutes(app: Express): Promise<Server> {
       const controller = new AbortController();
       const timeoutId = setTimeout(() => controller.abort(), 60000); // 60 secondes
 
-      console.log('🌐 BAP: Envoi vers webhook n8n (GET)...');
+      console.log('🌐 BAP: Envoi vers webhook n8n (POST avec body JSON)...');
       
       const response = await fetch(webhookUrl, {
-        method: 'GET',
+        method: 'POST',
         headers: {
-          'Content-Type': 'application/json',
-          'X-PDF-Base64': pdfBase64,
-          'X-Recipient': recipient,
-          'X-FileName': fileName,
-          'X-FileSize': fileBuffer.length.toString()
+          'Content-Type': 'application/json'
         },
+        body: JSON.stringify(webhookPayload),
         signal: controller.signal
       });