fix: surface exit code from spawned process

patch: added dotenv sample configuration and command to run locally

fix: added timeout_seconds input and handle timeout properly

sample.env

@@ -0,0 +1,6 @@
+INPUT_TIMEOUT_MINUTES=1
+INPUT_MAX_ATTEMPTS=3
+INPUT_COMMAND="node -e 'process.exit(99)'"
+INPUT_RETRY_WAIT_SECONDS=10
+INPUT_POLLING_INTERVAL_SECONDS=1
+INPUT_RETRY_ON=any