The same defect has now appeared twice: detect_current_act was fixed in Bug 28,
wait_for_town_spawn kept it, and nothing linked the two. These tests assert the
invariant for both, so a future fix to one cannot silently leave the other
behind:
- both must require _ACT_DETECT_MARGIN over the best rival-act marker
- both must score own-act and rival markers on ONE image (scores from two
different grabs are not comparable — the character can move between them)
- ambiguous detection must return None rather than guess
Audited every other TOWN_MARKERS consumer: bot.py:561 and main_menu.py:40/61
use best_match only as a boolean "are we in town?" check and never derive an
act, so they need no margin.
Co-Authored-By: Claude Opus 5 <[email protected]>
