- Add slug/short_id fields to database with auto-generation

- Create migration script for existing data
- Update admin interface to show only short URLs
- Implement redirect system to avoid code duplication
- Maintain backward compatibility with old URLs

src/app/p/[slug]/success/page.tsx

@@ -0,0 +1,46 @@
+'use client';
+
+import { Card, CardContent } from '@/components/ui/card';
+import { Button } from '@/components/ui/button';
+import { CheckCircle, ArrowLeft } from 'lucide-react';
+import Link from 'next/link';
+import { useParams } from 'next/navigation';
+
+export default function ProposeSuccessPage() {
+  const params = useParams();
+  const slug = params.slug as string;
+
+  return (
+    <div className="min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100 dark:from-slate-900 dark:to-slate-800 flex items-center justify-center py-8 px-4">
+      <Card className="w-full max-w-md shadow-lg">
+        <CardContent className="p-8 text-center">
+          <CheckCircle className="w-16 h-16 text-green-500 mx-auto mb-6" />
+          
+          <h1 className="text-2xl font-bold text-gray-900 dark:text-gray-100 mb-4">
+            Proposition soumise avec succès !
+          </h1>
+          
+          <p className="text-gray-600 dark:text-gray-400 mb-6">
+            Votre proposition a été enregistrée et sera examinée par l'équipe organisatrice.
+            Vous recevrez une confirmation par email.
+          </p>
+          
+          <div className="space-y-3">
+            <Button asChild className="w-full">
+              <Link href={`/p/${slug}`}>
+                <ArrowLeft className="w-4 h-4 mr-2" />
+                Déposer une autre proposition
+              </Link>
+            </Button>
+            
+            <Button variant="outline" asChild className="w-full">
+              <Link href="/">
+                Retour à l'accueil
+              </Link>
+            </Button>
+          </div>
+        </CardContent>
+      </Card>
+    </div>
+  );
+}