Add ambient sound system and eliminate log spam

- Implement AmbientSoundManager with tavern/outdoor ambience
- Fix audio buffer limit (5s → 60s) for long ambient loops
- Set log level to INFO to eliminate DEBUG spam (130MB → 3.2MB logs)
- Remove excessive terrain/model/network logging
- Fix ambient sound timer sharing and pitch parameter bugs

src/pipeline/m2_loader.cpp

@@ -823,11 +823,6 @@ bool M2Loader::loadSkin(const std::vector<uint8_t>& skinData, M2Model& model) {
         core::Logger::getInstance().debug("  Submeshes: ", submeshes.size());
         for (size_t i = 0; i < submeshes.size(); i++) {
             const auto& sm = submeshes[i];
-            core::Logger::getInstance().info("  SkinSection[", i, "]: id=", sm.id,
-                " level=", sm.level,
-                " vtxStart=", sm.vertexStart, " vtxCount=", sm.vertexCount,
-                " idxStart=", sm.indexStart, " idxCount=", sm.indexCount,
-                " boneCount=", sm.boneCount, " boneStart=", sm.boneStart);
         }
     }