Drop chains, enhancement tiers and map placements are live

The promised planes shipped, all measured from client build naeu-2026-08-03: every NPC page with a drop table now shows named 'Known drops' chips (93.8% of drop-table references resolve, verified two independent ways); the enhancement planner renders real ItemUpgrade tiers; and 22 map regions carry PK-validated entity placements with world coordinates at the world map.