Progress logging helpers (create_progress_tracker, log_progress) are now exported from
spark_fuse.utils.progress, making it easy to add elapsed-time bars to notebooks.
The data-processing template uses DataFrame.write.change_tracking (with schema evolution) by
default and shows Delta history before and after writes for quick debugging.
No code changes required for existing pipelines. Notebook users can import the new progress
helpers and adopt the refreshed template path (/tmp/spark_fuse/orders_enriched_ct) if desired.
Template write target renamed to /tmp/spark_fuse/orders_enriched_ct and now prefers
write.change_tracking with schema evolution enabled on Delta targets, falling back to Parquet
when Delta is unavailable.