fix: join detached cache work before embedded storage closes

README.md

@@ -127,6 +127,8 @@ For production, TAG ships manifests, Compose files, and guides under [`deploy/`]
 - **Parquet workloads** — caching parquet metadata ahead of the reader that needs it; see [docs/parquet-optimization.md](docs/parquet-optimization.md).
 - **Benchmarks** — see [docs/benchmarks.md](docs/benchmarks.md).
 
+On SIGINT or SIGTERM, TAG drains HTTP requests before joining detached cache work and closing embedded storage. A cache operation that does not return after cancellation can extend shutdown; see [Graceful shutdown](docs/deploy.md#graceful-shutdown).
+
 ## Architecture
 
 ```text

cmd/tag/main.go

@@ -399,5 +399,10 @@ func main() {
 		log.Error().Err(err).Msg("Error during server shutdown")
 	}
 
+	// HTTP draining stops new requests and waits for handlers, but detached
+	// cache work may still be using embedded storage. Seal and join that work
+	// before the deferred embeddedCache.Close runs.
+	service.Stop()
+
 	log.Info().Msg("TAG shutdown complete")
 }