ci(docker): simplify server image cleanup

scripts/server/deploy-docker-image.sh

@@ -68,19 +68,20 @@ prune_project_images() {
 
   echo "=== prune local project images: keep $retain_count for $tag_prefix ==="
 
-  docker image ls "$image_repo" \
-    --format '{{.Repository}}:{{.Tag}} {{.CreatedAt}}' \
+  if [ "$retain_count" -eq 1 ]; then
+    docker image ls "$image_repo" --format '{{.Repository}}:{{.Tag}} {{.ID}}' \
+      | awk -v prefix="$tag_prefix" -v current="$IMAGE" \
+          '$1 ~ ":" prefix && $1 !~ /-latest$/ && $1 != current { print $1 }' \
+      | xargs -r docker rmi || true
+    return 0
+  fi
+
+  docker image ls "$image_repo" --format '{{.Repository}}:{{.Tag}} {{.CreatedAt}}' \
     | awk -v prefix="$tag_prefix" '$1 ~ ":" prefix && $1 !~ /-latest$/ { print }' \
     | sort -k2,3r \
-    | awk -v keep="$retain_count" 'NR > keep { print $1 }' \
-    | while IFS= read -r old_image; do
-        [ -n "$old_image" ] || continue
-        if [ "$old_image" = "$IMAGE" ]; then
-          continue
-        fi
-        echo "Removing local image: $old_image"
-        docker image rm "$old_image" || true
-      done
+    | awk -v keep="$retain_count" -v current="$IMAGE" \
+        'NR > keep && $1 != current { print $1 }' \
+    | xargs -r docker rmi || true
 }
 
 prune_project_images "$SERVER_RETAIN_COUNT"