feat(adt): preserve MODF nameSet + scale fields across load/save round-trip

WMOPlacement struct gains nameSet and scale fields (defaulting to 0 and
1024 = 1.0). The loader now reads them when the entry is the full 64
bytes (WotLK+); the writer emits the actual values rather than always
hard-coding (0, 1024). Older expansions still round-trip cleanly because
defaults match the previous behaviour.

include/pipeline/adt_loader.hpp

@@ -113,6 +113,8 @@ struct ADTTerrain {
         float extentUpper[3];
         uint16_t flags;
         uint16_t doodadSet;
+        uint16_t nameSet = 0;     // MODF nameSet (rare; usually 0)
+        uint16_t scale = 1024;    // MODF scale * 1024 (1024 = 1.0)
     };
     std::vector<WMOPlacement> wmoPlacements;