Add super-admin Administration section and restructure global vs company settings

- Add Administration sidebar section (super-admin only) with Companies, Users, and Global Settings pages
- Add super-admin middleware, controllers, and API routes under /api/v1/super-admin/
- Allow super-admins to manage all companies and users across tenants
- Add user impersonation with short-lived tokens, audit logging, and UI banner
- Move system-level settings (Mail, PDF, Backup, Update, File Disk) from per-company to Administration > Global Settings
- Convert save_pdf_to_disk from CompanySetting to global Setting
- Add per-company mail configuration overrides (optional, falls back to global)
- Add CompanyMailConfigService to apply company mail config before sending emails

app/Models/Invoice.php

@@ -6,6 +6,7 @@ use App;
 use App\Facades\Hashids;
 use App\Facades\PDF;
 use App\Mail\SendInvoiceMail;
+use App\Services\CompanyMailConfigService;
 use App\Services\SerialNumberFormatter;
 use App\Space\PdfTemplateUtils;
 use App\Support\PdfHtmlSanitizer;
@@ -477,6 +478,8 @@ class Invoice extends Model implements HasMedia
     {
         $data = $this->sendInvoiceData($data);
 
+        CompanyMailConfigService::apply($this->company_id);
+
         $mail = \Mail::to($data['to']);
         if (! empty($data['cc'])) {
             $mail->cc($data['cc']);