feat(hermesagent): add hermes-setup helper script for first-time setup

- Add /usr/bin/hermes-setup that runs hermes setup as root, allowing
  optional components (TTS engines, browsers, etc.) to be installed,
  then restores ownership and permissions on /home/hermes
- Update login hint to reference hermes-setup
- Update completion message to guide users to hermes-setup and note
  that the gateway service should be installed as a user service
- Update JSON note to reflect new setup flow

json/hermesagent.json

@@ -42,7 +42,7 @@
             "type": "warning"
         },
         {
-            "text": "After container startup, login, switch to the hermes user (su - hermes) and run 'hermes setup' to configure your model provider and gateway server.",
+            "text": "After container startup, login as root and run 'hermes-setup' to configure your model provider and gateway server. When prompted to install the gateway service, install it as a user service (not a system service).",
             "type": "info"
         },
         {