fix: DOCKER_CMD function instead of string for proper arg passing

sg docker -c docker compose expands 'compose' as arg to sg, not docker.
Replaced with bash function docker_cmd() that uses sudo docker as fallback.
This works immediately after usermod without re-login.

install.sh

@@ -155,9 +155,9 @@ fi
 
 # Use sudo for docker commands if the current shell can't run docker directly
 if docker info &>/dev/null 2>&1; then
-  DOCKER_CMD="docker"
+  docker_cmd() { docker "$@"; }
 else
-  DOCKER_CMD="sg docker -c docker"
+  docker_cmd() { sudo docker "$@"; }
 fi
 
 # ── Clone / Pull ─────────────────────────────────
@@ -193,22 +193,22 @@ log "Data directory ready"
 
 # ── Build & Start ────────────────────────────────
 info "Building Docker image (this may take a few minutes)..."
-$DOCKER_CMD compose build web
+docker_cmd compose build web
 log "Build complete"
 
 info "Starting containers..."
-$DOCKER_CMD compose up -d
+docker_cmd compose up -d
 log "Containers are running"
 
 # ── Wait for health ──────────────────────────────
 info "Waiting for web service to be healthy..."
 for i in $(seq 1 30); do
-  if $DOCKER_CMD compose exec -T web wget --no-verbose --tries=1 --spider http://127.0.0.1:3000/api/health &>/dev/null; then
+  if docker_cmd compose exec -T web wget --no-verbose --tries=1 --spider http://127.0.0.1:3000/api/health &>/dev/null; then
     log "Web service is healthy"
     break
   fi
   if [ "$i" -eq 30 ]; then
-    warn "Timed out waiting for health check — check logs with: $DOCKER_CMD compose logs web"
+    warn "Timed out waiting for health check — check logs with: docker compose logs web"
   fi
   sleep 2
 done