The recipe conveyors (game_conveyor_<product>_epb) are placed as named child GameObjects
in the island_* prefabs (islands_assets_all.bundle), NOT via energy_grid (power grid only)
or any config asset. New extractor bundle/extract_conveyor_placements.py walks every island
prefab and cross-references production_lines.json -> extracted/conveyor_placements.json.
Result: Factorio (energyRods, 80mmT3Cannon, contactGrenades, armorPiercingRocket),
Kaiserplatz (energyRods, 40mmT3Cannon), Demo_Wunderinsel (70mmT3Cannon), DeusExMashineSmall
(computingModules, coralDust), testIsland(+Tramplers) (the 4 base test conveyors).
Corrects the earlier "Armory = Sprengstofffabrik hosts explosives" guess: the
LittleFactory/LittleFactoryArmory islands place NO recipe conveyors; grenades/rockets are
on Factorio. Unplaced blueprints: explosiveSmall, mechanicalParts (+ the plural
armorPiercingRockets, whose singular-named instance is on Factorio).
