docs: add repository URL and improve Related Repos section

README.md

 # Hermes Node Gateway Plugin
 
+**Repository:** `git@git.nexlab.net:lisa/hermes-node-gateway.git`  
+**Branch:** main  
+
+## Description
+
 Integrated node management plugin for Hermes Agent. Runs an embedded WebSocket server within the Hermes process to accept reverse connections from remote nodes.
 
 ## Features
@@ -276,6 +281,7 @@ The plugin runs as a background thread within the Hermes Agent process. It provi
 
 **Related Repositories**
 
+- **Gateway Plugin (this repo):** `git@git.nexlab.net:lisa/hermes-node-gateway.git`
 - **Node Agent:** `git@git.nexlab.net:lisa/hermes-node-agent.git`
 - **Chrome Extension:** `git@git.nexlab.net:lisa/hermes-node-chrome.git`