Refactor ESLint configuration and update code formatting: Standardize quotes in eslint.config.mjs, next.config.js, and various TypeScript files for consistency. Add Prettier as a dependency and include formatting scripts in package.json. Clean up unnecessary whitespace in multiple files to enhance code readability.

app/api/users/[id]/route.ts

@@ -35,7 +35,10 @@ export async function GET(
     });
 
     if (!user) {
-      return NextResponse.json({ error: "Utilisateur non trouvé" }, { status: 404 });
+      return NextResponse.json(
+        { error: "Utilisateur non trouvé" },
+        { status: 404 }
+      );
     }
 
     return NextResponse.json(user);
@@ -47,4 +50,3 @@ export async function GET(
     );
   }
 }
-