No existing test could tell a translated stat name apart from a raw
stat:upper() that never went through Strings() at all: every rose!
message assertion in the suite runs with no catalog loaded, where
Strings() is an identity function either way.
Loads a real catalog (Strings.load) that translates one stat name at a
time and checks it actually reaches the X-item, vitamin, and AI-trainer
X-item messages -- ROM-free, over tests/fixture_data. Confirmed this
catches the regression: reverting src/inventory/ItemEffects.lua and
src/battle/TrainerAI.lua to their pre-fix state fails 5 of 6 checks.
thibautbus