- InvoiceService::create() now auto-generates number if not provided
- Invoice list/show views fall back to billable.person.name_ar when
  contact_name is null (matches print view behavior)
- Fix participant link to use model route binding (uuid) not raw ID
- CSV export no longer restricts to current month by default — exports
  all invoices matching the active filters (status, search)
- CreateInvoiceWizard falls back to participantName for contact_name
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>