feat: add day-5 branded payment-failure reminder mailable

app/Mail/PaymentFailedDay5Reminder.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Mail;
+
+use App\Models\User;
+use App\Services\PlanFeatures;
+use Illuminate\Mail\Mailable;
+use Illuminate\Mail\Mailables\Content;
+use Illuminate\Mail\Mailables\Envelope;
+
+final class PaymentFailedDay5Reminder extends Mailable
+{
+    public function __construct(public readonly User $user) {}
+
+    public function envelope(): Envelope
+    {
+        $tier = PlanFeatures::for($this->user)->tier();
+
+        return new Envelope(
+            subject: 'Last chance — your '.ucfirst($tier).' features end tomorrow',
+        );
+    }
+
+    public function content(): Content
+    {
+        return new Content(
+            markdown: 'emails.payment-failed-day-5',
+            with: [
+                'name' => $this->user->name,
+                'tier' => PlanFeatures::for($this->user)->tier(),
+                'portalUrl' => route('billing.portal'),
+            ],
+        );
+    }
+}

resources/views/emails/payment-failed-day-5.blade.php

@@ -0,0 +1,27 @@
+<x-mail::message>
+# Your {{ ucfirst($tier) }} features end tomorrow
+
+Hi {{ $name }},
+
+Stripe has been trying to renew your subscription for the past few days without
+success. If the next retry doesn't go through, your **{{ ucfirst($tier) }}**
+subscription will be cancelled tomorrow and your account will move back to the
+Free tier.
+
+Here's what you'll lose on Free:
+
+- Smart fill-up / wait recommendations
+- Multi-channel alerts (WhatsApp, SMS, push)
+- Advanced fuel-price predictions
+
+You can keep everything running by updating your card now:
+
+<x-mail::button :url="$portalUrl">
+    Update payment method
+</x-mail::button>
+
+If you meant to cancel, no action needed — you'll just drop to Free automatically.
+
+Thanks for using FuelAlert,
+The FuelAlert Team
+</x-mail::message>