feat: Add company association to projects with role management

- Created Company model and migration with fields: name, tax_id, address, phone, email, website, type, notes
- Created company_project pivot table with role_in_project field
- Added relationships: Project.companies() and Company.projects()
- Created Livewire component ProjectCompanies for managing company assignments
- Added 'Companies' tab to project edit interface alongside Phases and Users tabs
- Implemented assign/remove company functionality with role selection
- Applied same permissions logic as user assignment (assign users permission or Admin role)

resources/views/livewire/project-edit-tabs.blade.php

@@ -18,6 +18,12 @@
         <label for="tab-users-{{ $project->id }}" class="tab {{ $activeTab === 'users' ? 'tab-active' : '' }}">
             {{ __('Users') }}
         </label>
+
+        <input type="radio" name="tabs-project-edit-{{ $project->id }}" id="tab-companies-{{ $project->id }}" 
+               {{ $activeTab === 'companies' ? 'checked' : '' }} class="tab-toggle" />
+        <label for="tab-companies-{{ $project->id }}" class="tab {{ $activeTab === 'companies' ? 'tab-active' : '' }}">
+            {{ __('Companies') }}
+        </label>
     </div>
 
     <!-- Tab Content -->