Root cause: params = reasoning_data.get('parameters', {}) created a reference
to the dictionary instead of a copy. When modifying params to add
product_names_joined, the change didn't persist because the database object
was immutable/read-only.
Changes:
- dashboard_service.py:408 - Create dict copy for PO params
- dashboard_service.py:632 - Create dict copy for batch params
- Added clean_old_dashboard_data.py utility script to remove old POs/batches
with malformed reasoning_data
The fix ensures template variables like {{supplier_name}}, {{product_names_joined}},
{{days_until_stockout}}, etc. are properly interpolated in the dashboard.
