feat(mail): add mailer interface with null and log drivers

src/Mail/Email.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Bazaar\Mail;
+
+final class Email
+{
+    public function __construct(
+        public readonly string $to,
+        public readonly string $subject,
+        public readonly string $body,
+        public readonly string $from = 'orders@bazaar.test'
+    ) {
+    }
+}

src/Mail/LogMailer.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Bazaar\Mail;
+
+final class LogMailer implements Mailer
+{
+    private array $sent = [];
+
+    public function __construct(private readonly string $logPath)
+    {
+    }
+
+    public function send(Email $email): void
+    {
+        $this->sent[] = $email;
+
+        $directory = dirname($this->logPath);
+        if (!is_dir($directory)) {
+            mkdir($directory, 0775, true);
+        }
+
+        $entry = sprintf(
+            "[%s] To: %s | From: %s | Subject: %s\n%s\n%s\n",
+            gmdate('c'),
+            $email->to,
+            $email->from,
+            $email->subject,
+            $email->body,
+            str_repeat('-', 60)
+        );
+        file_put_contents($this->logPath, $entry, FILE_APPEND | LOCK_EX);
+    }
+
+    public function sent(): array
+    {
+        return $this->sent;
+    }
+}

src/Mail/Mailer.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Bazaar\Mail;
+
+interface Mailer
+{
+    public function send(Email $email): void;
+
+    public function sent(): array;
+}

src/Mail/NullMailer.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Bazaar\Mail;
+
+final class NullMailer implements Mailer
+{
+    private array $sent = [];
+
+    public function send(Email $email): void
+    {
+        $this->sent[] = $email;
+    }
+
+    public function sent(): array
+    {
+        return $this->sent;
+    }
+}