fix: app cmd parsing, usage & tests

Note: the integration tests don't work due to ValidateApp still
attempting to validate the host key for the test app which doesn't
exist. This will be fixed in a future commit.

tests/integration/test_all.sh

@@ -16,7 +16,7 @@ run_test () {
     echo $logfile
 }
 
-testScripts=("app.sh" "autocomplete.sh" "catalogue.sh" "install.sh" "recipe.sh" "records.sh" "server.sh")
+testScripts=("app.sh" "autocomplete.sh" "catalogue.sh" "install.sh" "recipe.sh" "records.sh" "server.sh", "cmd.sh")
 
 for i in "${testScripts[@]}"; do
     cmd="./$i $res_dir${i/sh/log}"