Add transport system, fix NPC spawning, and improve water rendering

Transport System (Phases 1-7):
- Implement TransportManager with Catmull-Rom spline path interpolation
- Add WMO dynamic transforms for moving transport instances
- Implement player attachment via world position composition
- Add test transport with circular path around Stormwind harbor
- Add /transport board and /transport leave console commands
- Reuse taxi flight spline system and external follow camera mode

NPC Spawn Fixes:
- Add smart ocean spawn filter: blocks land creatures at high altitude over water (Z>50)
- Allow legitimate water creatures at sea level (Z≤50) to spawn correctly
- Fixes Elder Grey Bears, Highland Striders, and Plainscreepers spawning over ocean
- Snap online creatures to terrain height when valid ground exists

NpcManager Removal:
- Remove deprecated NpcManager (offline mode no longer supported)
- Delete npc_manager.hpp and npc_manager.cpp
- Simplify NPC animation callbacks to use only creatureInstances_ map
- Move NPC callbacks to game initialization in application.cpp

Water Rendering:
- Fix tile seam gaps caused by per-vertex wave randomization
- Add distance-based blending: seamless waves up close (<150u), grid effect far away (>400u)
- Smooth transition between seamless and grid modes (150-400 unit range)
- Preserves aesthetic grid pattern at horizon while eliminating gaps when swimming

include/core/application.hpp

@@ -14,7 +14,7 @@ namespace wowee {
 namespace rendering { class Renderer; }
 namespace ui { class UIManager; }
 namespace auth { class AuthHandler; }
-namespace game { class GameHandler; class World; class NpcManager; }
+namespace game { class GameHandler; class World; }
 namespace pipeline { class AssetManager; }
 namespace audio { enum class VoiceType; }
 
@@ -79,7 +79,6 @@ private:
     void render();
     void setupUICallbacks();
     void spawnPlayerCharacter();
-    void spawnNpcs();
     std::string getPlayerModelPath() const;
     static const char* mapIdToName(uint32_t mapId);
     void loadOnlineWorldTerrain(uint32_t mapId, float x, float y, float z);
@@ -93,6 +92,7 @@ private:
     void buildGameObjectDisplayLookups();
     std::string getGameObjectModelPathForDisplayId(uint32_t displayId) const;
     audio::VoiceType detectVoiceTypeFromDisplayId(uint32_t displayId) const;
+    void setupTestTransport();  // Test transport boat for development
 
     static Application* instance;
 
@@ -102,7 +102,6 @@ private:
     std::unique_ptr<auth::AuthHandler> authHandler;
     std::unique_ptr<game::GameHandler> gameHandler;
     std::unique_ptr<game::World> world;
-    std::unique_ptr<game::NpcManager> npcManager;
     std::unique_ptr<pipeline::AssetManager> assetManager;
 
     AppState state = AppState::AUTHENTICATION;