fix: undefined CROSS variable in cleanup dry-run mode

Changed CROSS to CROSS_MARK to match the variable defined in the
Unicode characters section (line 91).

This fixes the "CROSS: unbound variable" error when running the
cleanup function in dry-run mode.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

artifact_huggingface_download.sh

@@ -797,7 +797,7 @@ EOPYCLEANUP
             while IFS= read -r file; do
                 local basename
                 basename=$(basename "$file")
-                print_detail "  ${CROSS} Would delete: ${DIM}${basename}${RESET}"
+                print_detail "  ${CROSS_MARK} Would delete: ${DIM}${basename}${RESET}"
             done <<< "$files_to_delete"
         fi
         return 0