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

src/game/game_handler.cpp

@@ -1,4 +1,5 @@
 #include "game/game_handler.hpp"
+#include "game/transport_manager.hpp"
 #include "game/opcodes.hpp"
 #include "network/world_socket.hpp"
 #include "network/packet.hpp"
@@ -28,6 +29,9 @@ namespace game {
 GameHandler::GameHandler() {
     LOG_DEBUG("GameHandler created");
 
+    // Initialize transport manager
+    transportManager_ = std::make_unique<TransportManager>();
+
     // Default spells always available
     knownSpells.push_back(6603);  // Attack
     knownSpells.push_back(8690);  // Hearthstone
@@ -305,6 +309,11 @@ void GameHandler::update(float deltaTime) {
         auto taxiEnd = std::chrono::high_resolution_clock::now();
         taxiTime += std::chrono::duration<float, std::milli>(taxiEnd - taxiStart).count();
 
+        // Update transport manager
+        if (transportManager_) {
+            transportManager_->update(deltaTime);
+        }
+
         // Distance check timing
         auto distanceStart = std::chrono::high_resolution_clock::now();
 
@@ -6767,5 +6776,13 @@ void GameHandler::loadCharacterConfig() {
     }
 }
 
+glm::vec3 GameHandler::getComposedWorldPosition() {
+    if (playerTransportGuid_ != 0 && transportManager_) {
+        return transportManager_->getPlayerWorldPosition(playerTransportGuid_, playerTransportOffset_);
+    }
+    // Not on transport, return normal movement position
+    return glm::vec3(movementInfo.x, movementInfo.y, movementInfo.z);
+}
+
 } // namespace game
 } // namespace wowee