Add return types and typed parameters to remaining 10 models

Complete the type modernization across all models. Adds Builder-typed
$query parameters and return types to all scope methods, typed parameters
on accessors, and PHPDoc on scopePaginateData/scopeApplyFilters.

Models updated: Address, EstimateItem, Expense, ExpenseCategory,
InvoiceItem, Item, Note, Tax, TaxType, Unit.

5 models needed no changes (Country, Currency, ImpersonationLog,
Module, UserSetting) as they had no untyped public methods.

app/Models/EstimateItem.php

@@ -3,6 +3,7 @@
 namespace App\Models;
 
 use App\Traits\HasCustomFieldsTrait;
+use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
@@ -44,7 +45,7 @@ class EstimateItem extends Model
         return $this->hasMany(Tax::class);
     }
 
-    public function scopeWhereCompany($query, $company_id)
+    public function scopeWhereCompany(Builder $query, int $company_id): void
     {
         $query->where('company_id', $company_id);
     }