fix: calculate beat_phase for FlashEffect and refactor uniforms

- seq_compiler.py: Calculate beat_phase from beat_time (was hardcoded 0.0f)
- Refactor: Replace CommonPostProcessUniforms with UniformsSequenceParams
- Remove duplicate struct definition in post_process_helper.h
- Update all CNN effects and tests to use unified uniform struct
- Fixes FlashEffect showing solid white instead of flashing to beat

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

2 files changed, 2 insertions, 2 deletions

diff --git a/cnn_v1/src/cnn_v1_effect.cc b/cnn_v1/src/cnn_v1_effect.cc
index 1f44619..9118831 100644
--- a/cnn_v1/src/cnn_v1_effect.cc
+++ b/cnn_v1/src/cnn_v1_effect.cc
@@ -79,7 +79,7 @@ void CNNv1Effect::resize(int width, int height) {
 }
 
 void CNNv1Effect::render(WGPURenderPassEncoder pass,
-                       const CommonPostProcessUniforms& uniforms) {
+                       const UniformsSequenceParams& uniforms) {
   if (!bind_group_) {
     fprintf(stderr, "CNN render: no bind_group\n");
     return;
diff --git a/cnn_v1/src/cnn_v1_effect.h b/cnn_v1/src/cnn_v1_effect.h
index e820275..6753db8 100644
--- a/cnn_v1/src/cnn_v1_effect.h
+++ b/cnn_v1/src/cnn_v1_effect.h
@@ -26,7 +26,7 @@ class CNNv1Effect : public PostProcessEffect {
   void init(MainSequence* demo) override;
   void resize(int width, int height) override;
   void render(WGPURenderPassEncoder pass,
-              const CommonPostProcessUniforms& uniforms) override;
+              const UniformsSequenceParams& uniforms) override;
   void update_bind_group(WGPUTextureView input_view) override;
 
   // Layer 0 needs framebuffer capture for original input