fix: revert stride to 2 (correct for WotLK visible items), add re-emit tracing

Stride 4 was wrong — the raw dump shows entries at 284, 288, 292 which
are slots 0, 2, 4 with stride 2 (slot 1=NECK is zero because necks are
invisible). Stride 2 with base 284 correctly maps 19 equipment slots.

Added WARNING-level log when item query responses trigger equipment
re-emit for other players, to confirm the re-emit chain works.

The falling-through-world issue is likely terrain chunks not loading
fast enough — the terrain streaming stalls are still present.

include/game/game_handler.hpp

@@ -2573,7 +2573,7 @@ private:
     //   [284]=3817(Buckler) [288]=3808(Boots) [292]=3252 [296]=3823 [300]=3845 etc.
     // Each visible item occupies 4 fields: entry(1) + enchant(1) + padding(2).
     int visibleItemEntryBase_ = 284;
-    int visibleItemStride_ = 4;
+    int visibleItemStride_ = 2;
     bool visibleItemLayoutVerified_ = false;  // true once heuristic confirms/overrides default
     std::unordered_map<uint64_t, std::array<uint32_t, 19>> otherPlayerVisibleItemEntries_;
     std::unordered_set<uint64_t> otherPlayerVisibleDirty_;