perf: eliminate ~70 unnecessary sqrt ops per frame, optimize caches and threading

Squared distance optimizations across 30 files:
- Convert glm::length() comparisons to glm::dot() (no sqrt)
- Use glm::inversesqrt() for check-then-normalize patterns (1 rsqrt vs 2 sqrt)
- Defer sqrt to after early-out checks in collision/movement code
- Hottest paths: camera_controller (21), weather particles, WMO collision,
  transport movement, creature interpolation, nameplate culling

Container and algorithm improvements:
- std::map<string> → std::unordered_map for asset/DBC/MPQ/warden caches
- std::mutex → std::shared_mutex for asset_manager and mpq_manager caches
- std::sort → std::partial_sort in lighting_manager (top-2 of N volumes)
- Double-lookup find()+operator[] → insert_or_assign in game_handler
- Add reserve() for per-frame vectors: weather, swim_effects, WMO/M2 collision

Threading and synchronization:
- Replace 1ms busy-wait polling with condition_variable in character_renderer
- Move timestamp capture before mutex in logger
- Use memory_order_acquire/release for normal map completion signaling

API additions:
- DBC getStringView()/getStringViewByOffset() for zero-copy string access
- Parse creature display IDs from SMSG_CREATURE_QUERY_SINGLE_RESPONSE

include/game/world_packets.hpp

@@ -1502,9 +1502,10 @@ struct CreatureQueryResponseData {
     std::string subName;
     std::string iconName;
     uint32_t typeFlags = 0;
-    uint32_t creatureType = 0;
+    uint32_t creatureType = 0;  // 1=Beast, 2=Dragonkin, 3=Demon, 4=Elemental, 5=Giant, 6=Undead, 7=Humanoid, ...
     uint32_t family = 0;
     uint32_t rank = 0;         // 0=Normal, 1=Elite, 2=Rare Elite, 3=Boss, 4=Rare
+    uint32_t displayId[4] = {};  // Up to 4 random display models (0 = unused)
 
     bool isValid() const { return entry != 0 && !name.empty(); }
 };