fix(rendering): water reflection render pass compat, anisotropy feature, shadow pool race

Three bugs found via AMD RADV crash log:

1. Water reflection render pass used BOTTOM_OF_PIPE as srcStageMask but
   pipelines were created against the main pass (EARLY_FRAGMENT_TESTS |
   COLOR_ATTACHMENT_OUTPUT). AMD enforces strict render pass compatibility
   → SIGSEGV when scene renders into reflection texture.

2. samplerAnisotropy was never enabled during device creation despite being
   used in sampler creation — now requested via PhysicalDeviceSelector.

3. Shadow texture descriptor pool was reset each frame while prior frame's
   command buffers might still reference it. Split into per-frame-slot pools
   so each reset is fence-guarded.

include/rendering/m2_renderer.hpp

@@ -391,8 +391,9 @@ private:
     VkDescriptorSet shadowParamsSet_ = VK_NULL_HANDLE;
     ::VkBuffer shadowParamsUBO_ = VK_NULL_HANDLE;
     VmaAllocation shadowParamsAlloc_ = VK_NULL_HANDLE;
-    // Per-frame pool for foliage shadow texture descriptor sets
+    // Per-frame pools for foliage shadow texture descriptor sets (one per frame-in-flight)
-    VkDescriptorPool shadowTexPool_ = VK_NULL_HANDLE;
+    static constexpr uint32_t kShadowTexPoolFrames = 2;
+    VkDescriptorPool shadowTexPool_[kShadowTexPoolFrames] = {};
 
     // Particle pipelines
     VkPipeline particlePipeline_ = VK_NULL_HANDLE;       // M2 emitter particles

src/rendering/m2_renderer.cpp

@@ -814,7 +814,7 @@ void M2Renderer::shutdown() {
     // Destroy shadow resources
     destroyPipeline(shadowPipeline_);
     if (shadowPipelineLayout_) { vkDestroyPipelineLayout(device, shadowPipelineLayout_, nullptr); shadowPipelineLayout_ = VK_NULL_HANDLE; }
-    if (shadowTexPool_) { vkDestroyDescriptorPool(device, shadowTexPool_, nullptr); shadowTexPool_ = VK_NULL_HANDLE; }
+    for (auto& pool : shadowTexPool_) { if (pool) { vkDestroyDescriptorPool(device, pool, nullptr); pool = VK_NULL_HANDLE; } }
     if (shadowParamsPool_) { vkDestroyDescriptorPool(device, shadowParamsPool_, nullptr); shadowParamsPool_ = VK_NULL_HANDLE; }
     if (shadowParamsLayout_) { vkDestroyDescriptorSetLayout(device, shadowParamsLayout_, nullptr); shadowParamsLayout_ = VK_NULL_HANDLE; }
     if (shadowParamsUBO_) { vmaDestroyBuffer(alloc, shadowParamsUBO_, shadowParamsAlloc_); shadowParamsUBO_ = VK_NULL_HANDLE; }
@@ -2939,7 +2939,7 @@ bool M2Renderer::initializeShadow(VkRenderPass shadowRenderPass) {
     writes[1].pBufferInfo = &bufInfo;
     vkUpdateDescriptorSets(device, 2, writes, 0, nullptr);
 
-    // Per-frame pool for foliage shadow texture sets (reset each frame)
+    // Per-frame pools for foliage shadow texture sets (one per frame-in-flight, reset each frame)
     {
         VkDescriptorPoolSize texPoolSizes[2]{};
         texPoolSizes[0].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
@@ -2951,9 +2951,11 @@ bool M2Renderer::initializeShadow(VkRenderPass shadowRenderPass) {
         texPoolCI.maxSets = 256;
         texPoolCI.poolSizeCount = 2;
         texPoolCI.pPoolSizes = texPoolSizes;
-        if (vkCreateDescriptorPool(device, &texPoolCI, nullptr, &shadowTexPool_) != VK_SUCCESS) {
+        for (uint32_t f = 0; f < kShadowTexPoolFrames; ++f) {
-            LOG_ERROR("M2Renderer: failed to create shadow texture pool");
+            if (vkCreateDescriptorPool(device, &texPoolCI, nullptr, &shadowTexPool_[f]) != VK_SUCCESS) {
-            return false;
+                LOG_ERROR("M2Renderer: failed to create shadow texture pool ", f);
+                return false;
+            }
         }
     }
 
@@ -3029,9 +3031,11 @@ void M2Renderer::renderShadow(VkCommandBuffer cmd, const glm::mat4& lightSpaceMa
 
     const float shadowRadiusSq = shadowRadius * shadowRadius;
 
-    // Reset per-frame texture descriptor pool for foliage alpha-test sets
+    // Reset this frame slot's texture descriptor pool (safe: fence was waited on in beginFrame)
-    if (shadowTexPool_) {
+    const uint32_t frameIdx = vkCtx_->getCurrentFrame();
-        vkResetDescriptorPool(vkCtx_->getDevice(), shadowTexPool_, 0);
+    VkDescriptorPool curShadowTexPool = shadowTexPool_[frameIdx];
+    if (curShadowTexPool) {
+        vkResetDescriptorPool(vkCtx_->getDevice(), curShadowTexPool, 0);
     }
     // Cache: texture imageView -> allocated descriptor set (avoids duplicates within frame)
     // Reuse persistent map — pool reset already invalidated the sets.
@@ -3046,7 +3050,7 @@ void M2Renderer::renderShadow(VkCommandBuffer cmd, const glm::mat4& lightSpaceMa
         VkDescriptorSet set = VK_NULL_HANDLE;
         VkDescriptorSetAllocateInfo ai{};
         ai.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
-        ai.descriptorPool = shadowTexPool_;
+        ai.descriptorPool = curShadowTexPool;
         ai.descriptorSetCount = 1;
         ai.pSetLayouts = &shadowParamsLayout_;
         if (vkAllocateDescriptorSets(vkCtx_->getDevice(), &ai, &set) != VK_SUCCESS) {

src/rendering/vk_context.cpp

@@ -279,8 +279,11 @@ bool VkContext::createSurface(SDL_Window* window) {
 
 bool VkContext::selectPhysicalDevice() {
     vkb::PhysicalDeviceSelector selector{vkbInstance_};
+    VkPhysicalDeviceFeatures requiredFeatures{};
+    requiredFeatures.samplerAnisotropy = VK_TRUE;
     selector.set_surface(surface)
             .set_minimum_version(1, 1)
+            .set_required_features(requiredFeatures)
             .prefer_gpu_device_type(vkb::PreferredDeviceType::discrete);
 
     auto physRet = selector.select();

src/rendering/water_renderer.cpp

@@ -1784,7 +1784,7 @@ void WaterRenderer::createReflectionResources() {
     VkSubpassDependency dep{};
     dep.srcSubpass = VK_SUBPASS_EXTERNAL;
     dep.dstSubpass = 0;
-    dep.srcStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
+    dep.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
     dep.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
     dep.srcAccessMask = 0;
     dep.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;