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.

app/Services/Module/Module.php

@@ -1,75 +0,0 @@
-<?php
-
-namespace App\Services\Module;
-
-class Module
-{
-    /**
-     * All of the registered Modules scripts.
-     *
-     * @var array
-     */
-    public static $scripts = [];
-
-    /**
-     * All of the registered company settings.
-     *
-     * @var array
-     */
-    public static $settings = [];
-
-    /**
-     * All of the registered Modules CSS.
-     *
-     * @var array
-     */
-    public static $styles = [];
-
-    /**
-     * Register the given script file with Module.
-     *
-     * @param  string  $name
-     * @param  string  $path
-     * @return static
-     */
-    public static function script($name, $path)
-    {
-        static::$scripts[$name] = $path;
-
-        return new static;
-    }
-
-    /**
-     * Register the given CSS file with Module.
-     *
-     * @param  string  $name
-     * @param  string  $path
-     * @return static
-     */
-    public static function style($name, $path)
-    {
-        static::$styles[$name] = $path;
-
-        return new static;
-    }
-
-    /**
-     * Get all of the additional scripts that should be registered.
-     *
-     * @return array
-     */
-    public static function allScripts()
-    {
-        return static::$scripts;
-    }
-
-    /**
-     * Get all of the additional stylesheets that should be registered.
-     *
-     * @return array
-     */
-    public static function allStyles()
-    {
-        return static::$styles;
-    }
-}

app/Services/Module/ModuleFacade.php

@@ -1,18 +0,0 @@
-<?php
-
-namespace App\Services\Module;
-
-use Illuminate\Support\Facades\Facade as BaseFacade;
-
-class ModuleFacade extends BaseFacade
-{
-    /**
-     * Get the registered name of the component.
-     *
-     * @return string
-     */
-    protected static function getFacadeAccessor()
-    {
-        return Module::class;
-    }
-}