feat(api): organisation email branding and shared mail layout

- Add email branding columns to organisations table (logo, color, reply-to, sender name, footer)
- Create MailBrandingService for resolving per-org branding with defaults
- Create CrewliMailable abstract base class with branded from/reply-to
- Create shared Blade layout (mail.layouts.crewli) with inline CSS
- Refactor Registration*Mail and InvitationMail to extend CrewliMailable
- Add config/crewli.php for platform-wide defaults (portal_url, app_url, logo)
- Add dev-only /mail-preview/{type} route for browser email previewing
- Update Organisation model, resource, and form requests with branding fields

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/Mail/RegistrationRejectedMail.php

@@ -6,23 +6,22 @@ namespace App\Mail;
 
 use App\Models\Event;
 use App\Models\Person;
-use Illuminate\Bus\Queueable;
-use Illuminate\Contracts\Queue\ShouldQueue;
-use Illuminate\Mail\Mailable;
 use Illuminate\Mail\Mailables\Content;
 use Illuminate\Mail\Mailables\Envelope;
-use Illuminate\Queue\SerializesModels;
 
-final class RegistrationRejectedMail extends Mailable implements ShouldQueue
+final class RegistrationRejectedMail extends CrewliMailable
 {
-    use Queueable;
-    use SerializesModels;
+    public Person $person;
+    public Event $event;
+    public ?string $reason;
 
-    public function __construct(
-        public readonly Person $person,
-        public readonly Event $event,
-        public readonly ?string $reason = null,
-    ) {}
+    public function __construct(Person $person, Event $event, ?string $reason = null)
+    {
+        parent::__construct($event->organisation);
+        $this->person = $person;
+        $this->event = $event;
+        $this->reason = $reason;
+    }
 
     public function envelope(): Envelope
     {
@@ -33,11 +32,13 @@ final class RegistrationRejectedMail extends Mailable implements ShouldQueue
 
     public function content(): Content
     {
+        $this->buildBranding();
+
         return new Content(
-            markdown: 'emails.registration-rejected',
+            view: 'mail.registration-rejected',
             with: [
-                'personName' => $this->person->first_name,
-                'eventName' => $this->event->name,
+                'person' => $this->person,
+                'event' => $this->event,
                 'reason' => $this->reason,
             ],
         );