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>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/app/test_demo.cc b/src/app/test_demo.cc
index cf1a577..83e6f8b 100644
--- a/src/app/test_demo.cc
+++ b/src/app/test_demo.cc
@@ -95,7 +95,7 @@ class PeakMeterEffect : public PostProcessEffectV2 {
   }
 
   void render(WGPURenderPassEncoder pass,
-              const CommonPostProcessUniforms& uniforms) override {
+              const UniformsSequenceParams& uniforms) override {
     uniforms_.update(ctx_.queue, uniforms);
     PostProcessEffect::render(pass, uniforms);
   }