fix: double-free of external views in NodeRegistry and PASSTHROUGH shader test

- NodeRegistry: skip external nodes (texture==nullptr) in ~NodeRegistry()
  and resize() to avoid double-releasing views set via set_external_view()
- test_shader_assets: update PASSTHROUGH check to match #include pattern

handoff(Claude): 35/35 tests passing.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2 files changed, 6 insertions, 7 deletions

diff --git a/src/gpu/sequence.cc b/src/gpu/sequence.cc
index 9de4133..783f3df 100644
--- a/src/gpu/sequence.cc
+++ b/src/gpu/sequence.cc
@@ -30,15 +30,14 @@ NodeRegistry::NodeRegistry(WGPUDevice device, int default_width,
 
 NodeRegistry::~NodeRegistry() {
   for (auto& [name, node] : nodes_) {
+    if (node.texture == nullptr) continue; // External view, not owned
     if (node.view) {
       wgpuTextureViewRelease(node.view);
     }
     for (auto& mip_view : node.mip_views) {
       wgpuTextureViewRelease(mip_view);
     }
-    if (node.texture) {
-      wgpuTextureRelease(node.texture);
-    }
+    wgpuTextureRelease(node.texture);
   }
 }
 
@@ -108,6 +107,7 @@ void NodeRegistry::resize(int width, int height) {
   default_height_ = height;
 
   for (auto& [name, node] : nodes_) {
+    if (node.texture == nullptr) continue; // External view, not owned
     // Release old texture
     if (node.view) {
       wgpuTextureViewRelease(node.view);
@@ -115,9 +115,7 @@ void NodeRegistry::resize(int width, int height) {
     for (auto& mip_view : node.mip_views) {
       wgpuTextureViewRelease(mip_view);
     }
-    if (node.texture) {
-      wgpuTextureRelease(node.texture);
-    }
+    wgpuTextureRelease(node.texture);
 
     // Recreate with new dimensions
     node.width = width;
diff --git a/src/tests/gpu/test_shader_assets.cc b/src/tests/gpu/test_shader_assets.cc
index 63f9b5d..084694d 100644
--- a/src/tests/gpu/test_shader_assets.cc
+++ b/src/tests/gpu/test_shader_assets.cc
@@ -62,7 +62,8 @@ int main() {
                       {"@vertex", "vs_main", "@fragment", "fs_main"});
   all_passed &=
       validate_shader(AssetId::ASSET_SHADER_PASSTHROUGH, "PASSTHROUGH",
-                      {"@vertex", "vs_main", "@fragment", "fs_main"});
+                      {"#include \"render/fullscreen_uv_vs\"", "@fragment",
+                       "fs_main"});
   all_passed &= validate_shader(
       AssetId::ASSET_SHADER_ELLIPSE, "ELLIPSE",
       {"#include \"render/fullscreen_vs\"", "@fragment", "fs_main"});