melodic-software Purpose
Take one export file and produce one import file. Report what changed in the conversion, and refuse rather than guess when a column is missing.
Before converting
Read the header row and compare it against the expected column set. A missing column is a stop, not a default: a ledger row with a silently defaulted amount is worse than no row.
Dates
The export writes dates in the locale of whoever produced it. Parse against the declared locale in the file's own header, never against the machine's. Where the header declares none, ask.
Output
Write beside the input, never over it. Name the output for the input plus the target format, so two conversions of the same export do not collide.