generalize runtime ownership with doctor and local skill migration

bin/mosaic-prune-legacy-runtime

@@ -80,12 +80,12 @@ while IFS= read -r -d '' bak; do
 
   count_deletable=$((count_deletable + 1))
   if [[ $APPLY -eq 1 ]]; then
-    rm -f "$bak"
+    rm -rf "$bak"
     echo "[mosaic-prune] deleted: $bak"
   else
     echo "[mosaic-prune] would delete: $bak"
   fi
-done < <(find "$TARGET_ROOT" -type f -name '*.mosaic-bak-*' -print0)
+done < <(find "$TARGET_ROOT" \( -type f -o -type d \) -name '*.mosaic-bak-*' -print0)
 
 if [[ $APPLY -eq 1 ]]; then
   echo "[mosaic-prune] complete: deleted=$count_deletable candidates=$count_candidates runtime=$RUNTIME"