feat: complete email infrastructure with queue, templates, logging, and API

Adds the full transactional email system:
- Redis queue (QUEUE_CONNECTION=redis), SES config in .env.example
- 3 migrations: organisation_email_settings, organisation_email_templates, email_logs
- EmailTemplateType and EmailLogStatus enums with Dutch defaults
- EmailService as central entry point for all email sending
- SendTransactionalEmail queued job with retries and idempotency
- TransactionalMail mailable with responsive HTML + plain text templates
- Organisation-level branding (colors, logo, footer, reply-to)
- Per-type template overrides with {variable} substitution
- Email log with filtering by status, type, date range, recipient
- Preview and send-test endpoints for template management
- API endpoints: email-settings, email-templates (CRUD), email-logs (read-only)
- Integrated into existing flows: invitations, password reset, email
  verification, registration approval/rejection
- 37 new tests across 4 test files, all existing tests updated

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

api/app/Http/Controllers/Api/V1/OrganisationEmailSettingsController.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Controllers\Api\V1;
+
+use App\Http\Controllers\Controller;
+use App\Http\Requests\Api\V1\UpdateEmailSettingsRequest;
+use App\Http\Resources\Api\V1\EmailSettingsResource;
+use App\Models\Organisation;
+use App\Models\OrganisationEmailSettings;
+use App\Services\EmailService;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Support\Facades\Gate;
+
+final class OrganisationEmailSettingsController extends Controller
+{
+    public function __construct(
+        private readonly EmailService $emailService,
+    ) {}
+
+    public function show(Organisation $organisation): JsonResponse
+    {
+        Gate::authorize('update', $organisation);
+
+        $settings = $organisation->emailSettings;
+
+        if (! $settings) {
+            // Return defaults when no custom settings exist
+            return $this->success($this->emailService->resolveBranding($organisation));
+        }
+
+        return $this->success(new EmailSettingsResource($settings));
+    }
+
+    public function update(UpdateEmailSettingsRequest $request, Organisation $organisation): JsonResponse
+    {
+        Gate::authorize('update', $organisation);
+
+        $settings = OrganisationEmailSettings::updateOrCreate(
+            ['organisation_id' => $organisation->id],
+            $request->validated(),
+        );
+
+        activity('email_settings')
+            ->performedOn($settings)
+            ->causedBy($request->user())
+            ->log('email_settings.updated');
+
+        return $this->success(new EmailSettingsResource($settings->fresh()));
+    }
+}