main Dockerfile fixup (node version, libmagic)

Dockerfile

@@ -2,7 +2,7 @@
 # build ui #
 ############
 
-FROM node:20.8 AS build-ui
+FROM node:lts AS build-ui
 
 # env setup
 WORKDIR /usr/local/src/ovdashboard_ui
@@ -32,12 +32,18 @@ ENV \
   MODULE_NAME="ovdashboard_api.app"
 EXPOSE 8000
 
-# install ovdashboard_api
 COPY api ./
 RUN set -ex; \
+  # install libs
+  export DEBIAN_FRONTEND=noninteractive; \
+  apt-get update; apt-get install --yes --no-install-recommends \
+    libmagic1 \
+  ; rm -rf /var/lib/apt/lists/*; \
+  \
   # remove example app
   rm -rf /app; \
   \
+  # install ovdashboard_api
   python -m pip --no-cache-dir install ./
 
 # run as unprivileged user