improve WO form: inline client/vehicle create, mechanic filter, category translation, PDF emoji fix

- client_id field: switched to relationship() with createOptionForm so new clients
  can be created inline (name, phone, email); search also matches by phone
- vehicle_id field: added createOptionForm (make, model, plate, year, VIN); newly
  created vehicle is automatically linked to the currently selected client
- master_id field: now shows only active users with role mechanic/master
- WorksRelationManager: labor catalog select marked optional; added createOptionForm
  so new catalog entries can be added without leaving the WO form
- SubcontractJobsRelationManager: category table column now translates value via __()
  and shows explicit label(__('Categorie'))
- PDF work-order: replaced 📞 / ✉ / ⚠ emojis with plain-text equivalents so
  DomPDF/DejaVu Sans renders them correctly instead of showing "????"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

resources/views/pdf/work-order.blade.php

@@ -126,10 +126,10 @@
                     <div class="brand-sub">{{ $company->city }}</div>
                 @endif
                 @if ($company->phone)
-                    <div class="brand-sub">📞 {{ $company->phone }}</div>
+                    <div class="brand-sub">Tel.: {{ $company->phone }}</div>
                 @endif
                 @if ($company->email)
-                    <div class="brand-sub">✉ {{ $company->email }}</div>
+                    <div class="brand-sub">Email: {{ $company->email }}</div>
                 @endif
             </div>
             <div class="col col-half">
@@ -268,7 +268,7 @@
 
     @if ($wo->recommendations)
         <div class="recommendations">
-            <h3>{{ __('⚠ Recomandări') }}</h3>
+            <h3>{{ __('Recomandări') }}</h3>
             <div>{{ $wo->recommendations }}</div>
         </div>
     @endif