fix(discord): only send notifications in production

Prevent Discord release notifications from being sent in non-production
environments, avoiding accidental notifications during development and
testing. Added unit tests to verify the behavior.

tests/Unit/DiscordReleaseNotificationTest.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Tests\Unit;
+
+use App\Jobs\DiscordReleaseNotification;
+use Illuminate\Support\Facades\Http;
+use Tests\TestCase;
+
+class DiscordReleaseNotificationTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        Http::fake();
+        config([
+            'discord-alerts.webhook_urls.default' => 'https://discord.com/api/webhooks/test/123',
+        ]);
+    }
+
+    public function test_it_does_not_send_outside_production(): void
+    {
+        (new DiscordReleaseNotification('some-slug', 'release'))->handle();
+
+        Http::assertNothingSent();
+    }
+
+    public function test_it_sends_in_production(): void
+    {
+        app()->instance('env', 'production');
+
+        (new DiscordReleaseNotification('some-slug', 'release'))->handle();
+
+        Http::assertSent(function ($request) {
+            return str_contains($request->url(), 'https://discord.com/api/webhooks/test/123');
+        });
+    }
+}