Fix Laravel/PHP 'Class not found' (Composer Autoload)

Composer maps namespaces to folders via PSR-4. When PHP cannot find a class, the namespace and the file path have drifted apart, or the autoload map is stale.

Fix 1: Regenerate the Autoload Map

After adding new classes (especially outside the framework's known paths), rebuild Composer's map:

composer dump-autoload

Fix 2: Match Namespace to Folder Exactly

// File: app/Services/PaymentService.php
namespace App\Services;   // ✅ matches the folder (App\Services)

class PaymentService { /* ... */ }

PSR-4 maps App\ to app/. So App\Services\PaymentService must live at app/Services/PaymentService.php — with that exact casing.

Fix 3: Check composer.json PSR-4 Roots

"autoload": {
    "psr-4": { "App\\": "app/" }
}