Enhance Docker configuration with UID and GID arguments for improved user permissions

Dockerfile

@@ -23,9 +23,12 @@ FROM mwader/static-ffmpeg:latest AS ffmpeg
 
 FROM alpine:3.23
 
+ARG XTEVE_UID=1000
+ARG XTEVE_GID=1000
+
 RUN apk add --no-cache ca-certificates tzdata \
-  && addgroup -S xteve \
-  && adduser -S -G xteve xteve \
+  && addgroup -S -g "${XTEVE_GID}" xteve \
+  && adduser -S -D -H -u "${XTEVE_UID}" -G xteve xteve \
   && mkdir -p /xteve/config \
   && chown -R xteve:xteve /xteve