feat: add CategoryImporter service and SeedCategoriesCommand for seeding category data

- Implemented CategoryImporter service to handle bulk export/import logic for categories.
- Created SeedCategoriesCommand to seed category tables from JSON files in data/seed/.
- Added validation and normalization for category data during import.
- Ensured proper error handling and user feedback during the seeding process.

src/Category/Command/SeedCategoriesCommand.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace App\Category\Command;
+
+use App\Category\Service\CategoryImporter;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+/**
+ * Seeds the category tables from the JSON files in data/seed/.
+ *
+ * The data ships inside this repo (data/seed/) so a from-scratch database can be
+ * populated with the canonical, valid categories without any external source.
+ * Bundles are seeded in dependency order (provinces → cities, specialties →
+ * doctor_services) and each is a strict wipe+replace via {@see CategoryImporter}.
+ *
+ *   ddev exec php bin/console app:seed-categories
+ */
+#[AsCommand(name: 'app:seed-categories', description: 'Seed category tables (provinces, cities, specialties, doctor services) from data/seed/*.json')]
+class SeedCategoriesCommand extends Command
+{
+    /** seed order matters: referenced tables first */
+    private const ORDER = ['provinces', 'cities', 'specialties', 'doctor_services'];
+
+    public function __construct(
+        private readonly CategoryImporter $importer,
+        private readonly string $projectDir,
+    ) {
+        parent::__construct();
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io     = new SymfonyStyle($input, $output);
+        $seedDir = $this->projectDir . '/data/seed';
+
+        foreach (self::ORDER as $bundle) {
+            $file = $seedDir . '/' . $bundle . '.json';
+            if (!is_file($file)) {
+                $io->error("فایل seed یافت نشد: {$file}");
+                return Command::FAILURE;
+            }
+
+            $payload = json_decode((string) file_get_contents($file), true);
+            if (!is_array($payload) || $payload === [] || array_keys($payload) !== range(0, count($payload) - 1)) {
+                $io->error("{$bundle}: فایل باید یک آرایه‌ی غیرخالی باشد");
+                return Command::FAILURE;
+            }
+
+            $normalized = [];
+            $errors = $this->importer->validate($bundle, $payload, $normalized);
+            if ($errors !== []) {
+                $io->error("{$bundle}: اعتبارسنجی ناموفق — " . count($errors) . ' خطا');
+                foreach (array_slice($errors, 0, 10) as $e) {
+                    $io->writeln("  • {$e['message']}");
+                }
+                return Command::FAILURE;
+            }
+
+            $this->importer->replace($bundle, $normalized);
+            $io->success(sprintf('%s: %d رکورد seed شد', $bundle, count($normalized)));
+        }
+
+        return Command::SUCCESS;
+    }
+}