refactor(gpu): Add RAII wrapper for WGPU resources to eliminate manual cleanup

Introduces WGPUResource template with automatic release on destruction.
Reduces boilerplate in effect destructors and prevents resource leaks.

- set() for one-time initialization
- replace() for per-frame recreation
- Field ordering documented for dependency management

Converted 3 effects (Heptagon, Flash, Passthrough) and Effect base class.
All tests pass (34/34).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/effects/passthrough_effect.h b/src/effects/passthrough_effect.h
index 3813fa8..1c60e02 100644
--- a/src/effects/passthrough_effect.h
+++ b/src/effects/passthrough_effect.h
@@ -4,6 +4,7 @@
 
 #include "gpu/effect.h"
 #include "gpu/uniform_helper.h"
+#include "gpu/wgpu_resource.h"
 
 class Passthrough : public Effect {
  public:
@@ -15,6 +16,6 @@ class Passthrough : public Effect {
               NodeRegistry& nodes) override;
 
  private:
-  WGPURenderPipeline pipeline_;
-  WGPUBindGroup bind_group_;
+  RenderPipeline pipeline_;
+  BindGroup bind_group_;
 };