refactor(modules): migrate asset registry from app/Services to invoiceshelf/modules package

The vestigial App\Services\Module\Module static class — with its unused
\$scripts / \$styles / \$settings registries — never had any of its helpers
wired up. The new InvoiceShelf\Modules\Registry shipped from the
invoiceshelf/modules package supersedes it cleanly: same static-array surface
(\$menu, \$settings, \$scripts, \$styles), but lives outside the host app so
third-party modules can depend on it without importing v3-app internals.

Three consumers in the host app are migrated to the new namespace:

- ScriptController and StyleController (the HTTP endpoints that serve
  module-registered JS/CSS assets at /modules/scripts/{name} and
  /modules/styles/{name}) now look up paths via Registry::scriptFor() and
  Registry::styleFor() instead of Arr::get(ModuleFacade::all*(), \$name).
  Also tightens type hints — Request import + Response return type.

- resources/views/app.blade.php iterates Registry::allStyles() /
  Registry::allScripts() to inject module-supplied <link>/<script> tags into
  the main layout. Same Akaunting-style asset injection mechanism, just
  reading from the new namespace.

Both Module and ModuleFacade are deleted — they had no remaining callers
after this migration.

resources/views/app.blade.php

@@ -17,7 +17,7 @@
     <meta name="csrf-token" content="{{ csrf_token() }}">
 
     <!-- Module Styles -->
-    @foreach(\App\Services\Module\ModuleFacade::allStyles() as $name => $path)
+    @foreach(\InvoiceShelf\Modules\Registry::allStyles() as $name => $path)
         <link rel="stylesheet" href="/modules/styles/{{ $name }}">
     @endforeach
 
@@ -38,7 +38,7 @@
     @if(isset($current_theme)) theme-{{ $current_theme }} @else theme-{{get_app_setting('admin_portal_theme') ?? 'invoiceshelf'}} @endif ">
 
     <!-- Module Scripts -->
-    @foreach (\App\Services\Module\ModuleFacade::allScripts() as $name => $path)
+    @foreach (\InvoiceShelf\Modules\Registry::allScripts() as $name => $path)
         @if (\Illuminate\Support\Str::startsWith($path, ['http://', 'https://']))
             <script type="module" src="{!! $path !!}"></script>
         @else