Add recipient email and milestone notifications on transfer create.

Recipients can be emailed the download link immediately and at optional
reminders (7/3/1 days before unavailable, or when grace period starts).

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/Feature/TransferRecipientMailTest.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Transfer;
+use App\Models\User;
+use App\Notifications\TransferRecipientNotification;
+use App\Services\Transfer\TransferRecipientMailService;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Http\UploadedFile;
+use Illuminate\Support\Facades\Notification;
+use Illuminate\Support\Facades\Storage;
+use Illuminate\Support\Str;
+use Tests\Concerns\FakesTransferBilling;
+use Tests\TestCase;
+
+class TransferRecipientMailTest extends TestCase
+{
+    use FakesTransferBilling;
+    use RefreshDatabase;
+
+    public function test_create_transfer_emails_recipient_when_created_milestone_selected(): void
+    {
+        Notification::fake();
+        Storage::fake('qr');
+        $this->fakeTransferBillingApi();
+
+        $user = User::create([
+            'public_id' => (string) Str::uuid(),
+            'name' => 'Sender',
+            'email' => 'sender+'.uniqid().'@example.com',
+        ]);
+
+        $this->actingAs($user)->post(route('transfer.transfers.store'), [
+            'title' => 'Project files',
+            'recipient_email' => 'recipient@example.com',
+            'email_milestones' => ['created'],
+            'files' => [UploadedFile::fake()->create('brief.pdf', 100, 'application/pdf')],
+        ])->assertRedirect();
+
+        Notification::assertSentOnDemand(
+            TransferRecipientNotification::class,
+            fn ($notification, $channels, $notifiable) => $notifiable->routes['mail'] === 'recipient@example.com',
+        );
+    }
+
+    public function test_recipient_day_milestone_is_sent_once(): void
+    {
+        Notification::fake();
+
+        $user = User::create([
+            'public_id' => (string) Str::uuid(),
+            'name' => 'Sender',
+            'email' => 'sender+'.uniqid().'@example.com',
+        ]);
+
+        $transfer = Transfer::create([
+            'user_id' => $user->id,
+            'title' => 'Reminder test',
+            'recipient_email' => 'recipient@example.com',
+            'recipient_email_milestones' => ['7'],
+            'recipient_milestones_sent' => [],
+            'retention_days' => 30,
+            'paid_until' => now()->addDays(7)->startOfDay(),
+            'status' => Transfer::STATUS_ACTIVE,
+            'storage_bytes' => 1024,
+        ]);
+
+        $service = app(TransferRecipientMailService::class);
+        $this->assertSame(1, $service->processDueMilestones());
+        $this->assertSame(0, $service->processDueMilestones());
+
+        $transfer->refresh();
+        $this->assertContains('7', $transfer->recipient_milestones_sent ?? []);
+
+        Notification::assertSentOnDemand(TransferRecipientNotification::class, 1);
+    }
+}