Money stops being a flat `coin` and becomes copper, stored as a single
int, formatted only at the display edge.
The approved model (1g = 100s = 10,000c, store everything in copper) said
money should stay an inventory item under one `copper` id. It can't. §6 is
what kills it: `give_item(x)` adds exactly 1 and carries no quantity, and
`gifts_given` is a global one-shot keyed by item id — so a single `copper`
id would be givable once, for one copper, for the whole campaign.
So the purse is one int on GameState, and the three denominations are
content items that exist only to let a bounded move name a unit —
give_item(gold) is +10,000c. Three ids, not three buckets: the
change-making problem never arises because there is only ever one number.
A quantity arg on the move was rejected — it hands the model an unbounded
integer to invent, which is the §2 line.
Currency routes to the purse and never enters `inventory`, so it can't
appear in an inventory grid by construction. No filter needed.
Prices remain content and remain M8.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QYa9u7Kdxv5gX4AnwWexy8
