Remove app/Space folder and extract model business logic into services

Relocate all 14 files from the catch-all app/Space namespace into proper
locations: data providers to Support/Formatters, installation utilities to
Services/Installation, PDF utils to Services/Pdf, module/update classes to
Services/Module and Services/Update, SiteApi trait to Traits, and helpers
to Support.

Extract ~1,400 lines of business logic from 8 fat models (Invoice, Payment,
Estimate, RecurringInvoice, Company, Customer, Expense, User) into 9 new
service classes with constructor injection. Controllers now depend on
services instead of calling static model methods. Shared item/tax creation
logic consolidated into DocumentItemService.

database/seeders/DemoSeeder.php

@@ -8,6 +8,7 @@ use App\Models\CompanySetting;
 use App\Models\Customer;
 use App\Models\Setting;
 use App\Models\User;
+use App\Services\CompanyService;
 use Illuminate\Database\Seeder;
 use Silber\Bouncer\BouncerFacade;
 
@@ -35,7 +36,7 @@ class DemoSeeder extends Seeder
 
         $company->unique_hash = Hashids::connection(Company::class)->encode($company->id);
         $company->save();
-        $company->setupDefaultData();
+        app(CompanyService::class)->setupDefaults($company);
         $user->companies()->attach($company->id);
         BouncerFacade::scope()->to($company->id);