feat : add Client entity with CRUD API

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

migrations/Version20260309213629.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20260309213629 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return '';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('CREATE TABLE client (id INT GENERATED BY DEFAULT AS IDENTITY NOT NULL, name VARCHAR(255) NOT NULL, email VARCHAR(255) DEFAULT NULL, phone VARCHAR(50) DEFAULT NULL, street VARCHAR(255) DEFAULT NULL, city VARCHAR(255) DEFAULT NULL, postal_code VARCHAR(20) DEFAULT NULL, PRIMARY KEY (id))');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('DROP TABLE client');
+    }
+}