Update service provider and facade to return unified AtpClient

src/AtpClientServiceProvider.php

···
 use SocialDept\AtpClient\Http\DPoPClient;
 use SocialDept\AtpClient\Session\SessionManager;
 use SocialDept\AtpClient\Storage\EncryptedFileKeyStore;
-use SocialDept\AtpClient\Client\Public\AtpPublicClient;
 
 class AtpClientServiceProvider extends ServiceProvider
 {
···
                     $this->app->instance(CredentialProvider::class, $provider);
                 }
 
-                public function public(?string $service = null): AtpPublicClient
+                public function public(?string $service = null): AtpClient
                 {
-                    return new AtpPublicClient(
-                        $service ?? config('atp-client.public.service_url', 'https://public.api.bsky.app')
+                    return new AtpClient(
+                        sessions: null,
+                        did: null,
+                        serviceUrl: $service ?? config('atp-client.public.service_url', 'https://public.api.bsky.app')
                     );
                 }
             };

src/Facades/Atp.php

···
 namespace SocialDept\AtpClient\Facades;
 
 use Illuminate\Support\Facades\Facade;
+use SocialDept\AtpClient\AtpClient;
 use SocialDept\AtpClient\Auth\OAuthEngine;
-use SocialDept\AtpClient\Client\AtpClient;
-use SocialDept\AtpClient\Client\Public\AtpPublicClient;
 use SocialDept\AtpClient\Contracts\CredentialProvider;
 
 /**
  * @method static AtpClient as(string $actor)
  * @method static AtpClient login(string $actor, string $password)
  * @method static OAuthEngine oauth()
- * @method static AtpPublicClient public(?string $service = null)
+ * @method static AtpClient public(?string $service = null)
  * @method static void setDefaultProvider(CredentialProvider $provider)
  *
  * @see \SocialDept\AtpClient\AtpClientServiceProvider