fix: improve node filtering by client base_version, set subscription content-type, and add hop_interval support for hysteria2

- Refactor node filtering logic to correctly handle client base_version requirements.
- Set appropriate Content-Type header for subscription responses.
- Add support for hop_interval configuration in hysteria2 node delivery.

app/Protocols/QuantumultX.php

@@ -24,7 +24,8 @@ class QuantumultX extends AbstractProtocol
                 $uri .= self::buildTrojan($user['uuid'], $item);
             }
         }
-        return response(base64_encode($uri), 200)
+        return response(base64_encode($uri))
+            ->header('content-type', 'text/plain')
             ->header('subscription-userinfo', "upload={$user['u']}; download={$user['d']}; total={$user['transfer_enable']}; expire={$user['expired_at']}");
     }