feat: add companies as top-level container for projects with departments

- Company → Project → (Locations + Departments) hierarchy
- Company CRUD (add, edit, delete) with AJAX
- Projects are created under a company via inline strip
- Two-column project body: Locations | Departments
- Stats show companies, projects, locations, departments, active projects
- Dynamic stat counters update on add/delete without page reload

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

app/Models/Settings/ProjectSetting.php

@@ -8,7 +8,7 @@ class ProjectSetting extends Model
 {
     protected $table = 'settings_projects';
 
-    protected $fillable = ['name', 'is_active'];
+    protected $fillable = ['name', 'is_active', 'company_id'];
 
     protected $casts = ['is_active' => 'boolean'];
 
@@ -17,6 +17,11 @@ class ProjectSetting extends Model
         return $query->where('is_active', true);
     }
 
+    public function company(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Company::class, 'company_id');
+    }
+
     public function locations(): \Illuminate\Database\Eloquent\Relations\HasMany
     {
         return $this->hasMany(\App\Models\Settings\Location::class, 'project_id');