Three independent code paths wrote to archive.cost with conflicting
strategies, causing the same model to produce different prices on each
reprint (e.g. £0.77, £1.54, £2.03).
- Remove add_reprint_cost (Path 3) — redundant cost accumulation that
double-counted on top of usage tracker
- Fix usage tracker (Path 2) — compute cost from current session's
results only, not a SUM of all historical SpoolUsageHistory rows
- Remove _reprint_archives tracking set from main.py
- Update test mocks to match simplified query pattern
archive.cost now always reflects the cost of a single print.
maziggy