Update production debugging guide for Avoirs module

Add a new markdown file to provide detailed debugging steps and solutions for production issues related to the Avoirs module, including database table creation, permission checks, and API testing.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 9fcf4b21-eb0c-4e53-a567-e2ce4a6ad869
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/9fcf4b21-eb0c-4e53-a567-e2ce4a6ad869/0C3uBiZ

client/src/pages/Avoirs.tsx

@@ -395,7 +395,7 @@ export default function Avoirs() {
           />
         </div>
         
-        {user?.role === 'admin' && (
+        {(user as any)?.role === 'admin' && (
           <Select value={selectedStoreId} onValueChange={setSelectedStoreId}>
             <SelectTrigger className="w-[200px]">
               <SelectValue placeholder="Tous les magasins" />