Add LaborCategory resource — manage labor categories from UI

- Creates labor_categories table (company-scoped) seeded with 11 defaults
- LaborCategory model with BelongsToTenant
- Full Filament CRUD resource with drag-to-reorder (sort_order)
- LaborResource category Select now reads from DB instead of hardcoded const
- Navigation: 'Categorii manopere' in Service group, sort 33

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

app/Models/Tenant/LaborCategory.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace App\Models\Tenant;
+
+use App\Models\Concerns\BelongsToTenant;
+use Illuminate\Database\Eloquent\Model;
+
+class LaborCategory extends Model
+{
+    use BelongsToTenant;
+
+    protected $fillable = ['company_id', 'name', 'sort_order'];
+
+    protected $casts = ['sort_order' => 'integer'];
+}