Remove old images by ID after container updates, not just dangling prune

Tagged images are never caught by docker image prune -f. Collect OLD_IDs
during the pull loop and explicitly rmi them after rebuilds complete.

Docker_Essentials/docker_update_remaining.sh

@@ -166,6 +166,7 @@ START=$(date +%s)
 UPDATED=()
 UP_TO_DATE=()
 FAILED=()
+OLD_IMAGE_IDS=()
 
 for container in "${REMAINING[@]}"; do
     [[ -z "$container" ]] && continue
@@ -202,6 +203,7 @@ for container in "${REMAINING[@]}"; do
         if [[ -n "$OLD_ID" ]] && [[ "$OLD_ID" != "$NEW_ID" ]]; then
             log "$ICON_DONE  $container — updated ✅ (${OLD_ID:7:12} → ${NEW_ID:7:12})"
             UPDATED+=("$container")
+            OLD_IMAGE_IDS+=("$OLD_ID")
         else
             log "$container — already up to date (${NEW_ID:7:12})"
             UP_TO_DATE+=("$container")
@@ -269,9 +271,12 @@ echo ""
 echo "━━━ $ICON_SYNC Pruning Dangling Images — $(date '+%Y-%m-%d %H:%M:%S') ━━━"
 
 if [[ "$DRY_RUN" == true ]]; then
-    warn "DRY RUN — would prune dangling images"
+    warn "DRY RUN — would remove ${#OLD_IMAGE_IDS[@]} old image(s) and prune dangling"
     PRUNED_SUMMARY="(dry run)"
 else
+    for _old_id in "${OLD_IMAGE_IDS[@]}"; do
+        docker rmi "$_old_id" >/dev/null 2>&1 || true
+    done
     PRUNED_OUTPUT=$(docker image prune -f 2>&1)
     [[ "$ENABLE_LOGGING" == "true" ]] && echo "$PRUNED_OUTPUT" | sed 's/^/  /'
     PRUNED_SUMMARY=$(echo "$PRUNED_OUTPUT" | grep -E "^Total reclaimed" || echo "nothing reclaimed")