feat: properly handle RPC errors

client.v

@@ -24,8 +24,9 @@ pub fn new_with_url(url string) &Client {
 	}
 }
 
-struct SuccessResponse {
-	result_count int       [json: resultCount]
+struct Response {
+	@type   string    [json: 'type']
+	error   string
 	results []Package
 }
 
@@ -45,7 +46,11 @@ fn (c Client) request(params map[string][]string) ?[]Package {
 		return error('error')
 	}
 
-	data := json.decode(SuccessResponse, res.body)?
+	data := json.decode(Response, res.body)?
+
+	if data.@type == 'error' {
+		return error('Server responded with an error: $data.error')
+	}
 
 	return data.results
 }