Fix water descriptor pool leak and add water rendering diagnostics

- Add VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT to water material
  descriptor pool so individual sets can be freed when tiles are unloaded
- Free descriptor sets in destroyWaterMesh() instead of leaking them
- Add terrain manager unloadAll() during logout to properly clear stale
  tiles, water surfaces, and queues between sessions
- Add diagnostic logging for water surface loading, material allocation
  failures, and render skip reasons to investigate missing water

include/rendering/water_renderer.hpp

@@ -172,6 +172,7 @@ private:
     VkImageView sceneDepthView = VK_NULL_HANDLE;
     VkExtent2D sceneHistoryExtent = {0, 0};
     bool sceneHistoryReady = false;
+    mutable uint32_t renderDiagCounter_ = 0;
 
     // Planar reflection resources
     static constexpr uint32_t REFLECTION_WIDTH = 512;

src/core/application.cpp

@@ -661,7 +661,10 @@ void Application::logoutToLogin() {
         if (auto* m2 = renderer->getM2Renderer()) {
             m2->clear();
         }
-        // TerrainManager will be re-initialized on next world entry
+        // Unload all terrain tiles + water surfaces so next world entry starts fresh
+        if (auto* terrain = renderer->getTerrainManager()) {
+            terrain->unloadAll();
+        }
         if (auto* questMarkers = renderer->getQuestMarkerRenderer()) {
             questMarkers->clear();
         }

src/rendering/terrain_manager.cpp

@@ -705,7 +705,15 @@ bool TerrainManager::advanceFinalization(FinalizingTile& ft) {
         // Load water immediately after terrain (same frame) — water is now
         // deduplicated to ~1-2 merged surfaces per tile, so this is fast.
         if (waterRenderer) {
+            size_t beforeSurfaces = waterRenderer->getSurfaceCount();
             waterRenderer->loadFromTerrain(pending->terrain, true, x, y);
+            size_t afterSurfaces = waterRenderer->getSurfaceCount();
+            if (afterSurfaces > beforeSurfaces) {
+                LOG_INFO("Water: tile [", x, ",", y, "] added ", afterSurfaces - beforeSurfaces,
+                         " surfaces (total: ", afterSurfaces, ")");
+            }
+        } else {
+            LOG_WARNING("Water: waterRenderer is null during tile [", x, ",", y, "] finalization!");
         }
 
         // Ensure M2 renderer has asset manager

src/rendering/water_renderer.cpp

@@ -76,6 +76,7 @@ bool WaterRenderer::initialize(VkContext* ctx, VkDescriptorSetLayout perFrameLay
 
     VkDescriptorPoolCreateInfo poolInfo{};
     poolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
+    poolInfo.flags = VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT;
     poolInfo.maxSets = MAX_WATER_SETS;
     poolInfo.poolSizeCount = 1;
     poolInfo.pPoolSizes = &poolSize;
@@ -541,6 +542,8 @@ void WaterRenderer::updateMaterialUBO(WaterSurface& surface) {
         write.pBufferInfo = &bufInfo;
 
         vkUpdateDescriptorSets(vkCtx->getDevice(), 1, &write, 0, nullptr);
+    } else {
+        LOG_WARNING("Water: failed to allocate material descriptor set (pool exhaustion?)");
     }
 }
 
@@ -802,8 +805,10 @@ void WaterRenderer::loadFromTerrain(const pipeline::ADTTerrain& terrain, bool ap
         totalSurfaces++;
     }
 
-    LOG_DEBUG("Water: Loaded ", totalSurfaces, " surfaces from tile [", tileX, ",", tileY,
-              "] (", mergeGroups.size(), " groups), total surfaces: ", surfaces.size());
+    if (totalSurfaces > 0) {
+        LOG_INFO("Water: Loaded ", totalSurfaces, " surfaces from tile [", tileX, ",", tileY,
+                 "] (", mergeGroups.size(), " groups), total surfaces: ", surfaces.size());
+    }
 }
 
 void WaterRenderer::removeTile(int tileX, int tileY) {
@@ -936,8 +941,21 @@ void WaterRenderer::clear() {
 void WaterRenderer::render(VkCommandBuffer cmd, VkDescriptorSet perFrameSet,
                             const Camera& /*camera*/, float /*time*/, bool use1x) {
     VkPipeline pipeline = (use1x && water1xPipeline) ? water1xPipeline : waterPipeline;
-    if (!renderingEnabled || surfaces.empty() || !pipeline) return;
-    if (!sceneSet) return;
+    if (!renderingEnabled || surfaces.empty() || !pipeline) {
+        if (renderDiagCounter_++ % 300 == 0 && !surfaces.empty()) {
+            LOG_WARNING("Water: render skipped — enabled=", renderingEnabled,
+                        " surfaces=", surfaces.size(),
+                        " pipeline=", (pipeline ? "ok" : "null"),
+                        " use1x=", use1x);
+        }
+        return;
+    }
+    if (!sceneSet) {
+        if (renderDiagCounter_++ % 300 == 0) {
+            LOG_WARNING("Water: render skipped — sceneSet is null, surfaces=", surfaces.size());
+        }
+        return;
+    }
 
     vkCmdBindPipeline(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
 
@@ -1251,6 +1269,9 @@ void WaterRenderer::destroyWaterMesh(WaterSurface& surface) {
         destroyBuffer(allocator, ab);
         surface.materialUBO = VK_NULL_HANDLE;
     }
+    if (surface.materialSet && materialDescPool) {
+        vkFreeDescriptorSets(vkCtx->getDevice(), materialDescPool, 1, &surface.materialSet);
+    }
     surface.materialSet = VK_NULL_HANDLE;
 }