feat: WOB→WMO conversion and loading in client terrain manager

- WoweeBuildingLoader::toWMOModel() converts WOB groups to WMOModel
  with vertices, indices, normals, texCoords, and vertex colors
- TerrainManager now loads WOB files from custom_zones/buildings/
  and converts to WMOModel for the WMO renderer pipeline
- WMOGroup indices converted from uint32 to uint16 for renderer compat

Client open format support — 4 of 6 now loading:
- FULL: WOT/WHM terrain, PNG textures, WOM models
- LOAD: WOB buildings (converts to WMOModel, render pipeline TODO)
- DETECT: zone.json (scanned), JSON DBC (scanned)

include/pipeline/wowee_building.hpp

@@ -53,6 +53,9 @@ public:
     static WoweeBuilding load(const std::string& basePath);
     static bool save(const WoweeBuilding& building, const std::string& basePath);
     static bool exists(const std::string& basePath);
+
+    // Convert WOB to WMOModel for the client's WMO renderer
+    static bool toWMOModel(const WoweeBuilding& building, class WMOModel& outModel);
 };
 
 } // namespace pipeline

src/pipeline/wowee_building.cpp

@@ -1,4 +1,5 @@
 #include "pipeline/wowee_building.hpp"
+#include "pipeline/wmo_loader.hpp"
 #include "core/logger.hpp"
 #include <fstream>
 #include <filesystem>
@@ -161,5 +162,39 @@ bool WoweeBuildingLoader::save(const WoweeBuilding& bld, const std::string& base
     return true;
 }
 
+bool WoweeBuildingLoader::toWMOModel(const WoweeBuilding& building, WMOModel& outModel) {
+    if (building.groups.empty()) return false;
+
+    outModel.nGroups = static_cast<uint32_t>(building.groups.size());
+    outModel.groups.clear();
+
+    for (const auto& grp : building.groups) {
+        WMOGroup wmoGroup;
+        wmoGroup.name = grp.name;
+
+        // Convert vertices
+        wmoGroup.vertices.reserve(grp.vertices.size());
+        for (const auto& v : grp.vertices) {
+            WMOVertex wv;
+            wv.position = v.position;
+            wv.normal = v.normal;
+            wv.texCoord = v.texCoord;
+            wv.color = v.color;
+            wmoGroup.vertices.push_back(wv);
+        }
+
+        // Convert indices
+        wmoGroup.indices.reserve(grp.indices.size());
+        for (uint32_t idx : grp.indices)
+            wmoGroup.indices.push_back(static_cast<uint16_t>(idx));
+
+        outModel.groups.push_back(std::move(wmoGroup));
+    }
+
+    // WMOModel uses isValid() = nGroups > 0 && !groups.empty()
+    // Both are now set, so isValid() will return true
+    return true;
+}
+
 } // namespace pipeline
 } // namespace wowee

src/rendering/terrain_manager.cpp

@@ -605,7 +605,14 @@ std::shared_ptr<PendingTile> TerrainManager::prepareTile(int x, int y) {
                 std::vector<std::string> wobPrefixes = {"custom_zones/buildings/", "output/" + mapName + "/buildings/"};
                 for (const auto& prefix : wobPrefixes) {
                     if (pipeline::WoweeBuildingLoader::exists(prefix + wobBase)) {
-                        LOG_INFO("WOB building found: ", prefix + wobBase, " (loading not yet implemented)");
+                        auto wob = pipeline::WoweeBuildingLoader::load(prefix + wobBase);
+                        if (wob.isValid()) {
+                            pipeline::WMOModel wobAsWmo;
+                            if (pipeline::WoweeBuildingLoader::toWMOModel(wob, wobAsWmo)) {
+                                LOG_INFO("Loaded WOB building: ", prefix + wobBase);
+                                // TODO: feed wobAsWmo into the WMO render pipeline
+                            }
+                        }
                         break;
                     }
                 }