updated the repo to use host networking as the default appliance deployment model

README.md

@@ -11,7 +11,7 @@ The target environment for this project is a host where services are started by
 `systemd`, including Docker-backed services. Marvis is intended to run the same
 way:
 
-- the FastAPI app runs on `127.0.0.1:8100`
+- the FastAPI app runs in a container with host networking on `127.0.0.1:8100`
 - Traefik exposes it at `/core/marvis/*`
 - `patch-ncm.py` injects the sidebar entries and iframe routes into the NCM UI
 - the injected entries should only be added for services that are actually
@@ -30,6 +30,8 @@ docker build -t p5g-marvis:latest .
 
 ```bash
 cp config/p5g-marvis.service /usr/lib/systemd/system/p5g-marvis.service
+mkdir -p /etc/p5g-marvis
+cp config/marvis.env.example /etc/p5g-marvis/marvis.env
 systemctl daemon-reload
 systemctl enable --now p5g-marvis
 ```
@@ -41,6 +43,14 @@ http://127.0.0.1:8100
 http://127.0.0.1:8100/api/docs
 ```
 
+Edit `/etc/p5g-marvis/marvis.env` per host instead of hardcoding addresses in the
+unit file. In particular:
+
+- set `MARVIS_PROMETHEUS_URL` and `MARVIS_ALERTMANAGER_URL` to the correct host
+  endpoints for that appliance
+- keep the defaults if Prometheus and Alertmanager are already available on host
+  loopback from the appliance network namespace
+
 ---
 
 ## Architecture Overview