feat: implement product variant CRUD operations and tenant configuration seeding

app/Domains/Shared/Rules/ImageOrBase64Rule.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace App\Domains\Shared\Rules;
+
+use Closure;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Http\UploadedFile;
+
+class ImageOrBase64Rule implements ValidationRule
+{
+    public function validate(string $attribute, mixed $value, Closure $fail): void
+    {
+        if ($value instanceof UploadedFile) {
+            $mime = $value->getMimeType();
+            if (! str_starts_with((string) $mime, 'image/')) {
+                $fail("The :attribute must be a valid image file.");
+            }
+            return;
+        }
+
+        if (is_string($value)) {
+            $payload = trim($value);
+
+            if ($payload === '') {
+                $fail("The :attribute must not be empty.");
+                return;
+            }
+
+            $declaredMimeType = null;
+            if (preg_match('/^data:(?<mime>[-\w.+\/]+);base64,(?<data>.+)$/s', $payload, $matches) === 1) {
+                $declaredMimeType = strtolower($matches['mime']);
+                $payload = $matches['data'];
+            }
+
+            $decoded = base64_decode(preg_replace('/\s+/', '', $payload), true);
+            if ($decoded === false || $decoded === '') {
+                $fail("The :attribute must be a valid base64-encoded image.");
+                return;
+            }
+
+            $finfo = new \finfo(FILEINFO_MIME_TYPE);
+            $detectedMime = $finfo->buffer($decoded);
+            $mime = $detectedMime ?: $declaredMimeType;
+
+            if (! $mime || ! str_starts_with((string) $mime, 'image/')) {
+                $fail("The :attribute must be a valid image (file or base64).");
+            }
+
+            return;
+        }
+
+        $fail("The :attribute must be an image file or a base64-encoded image string.");
+    }
+}