refactor: complete removal of 'Effect' suffix from C++ class names

Update effect class definitions in headers and implementations to match
timeline.seq naming convention. All tests passing (34/34).

Classes renamed:
- PassthroughEffect → Passthrough
- GaussianBlurEffect → GaussianBlur
- PlaceholderEffect → Placeholder
- HeptagonEffect → Heptagon
- ParticlesEffect → Particles
- RotatingCubeEffect → RotatingCube
- Hybrid3DEffect → Hybrid3D
- FlashEffect → Flash
- PeakMeterEffect → PeakMeter

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

1 files changed, 2 insertions, 2 deletions

diff --git a/src/effects/gaussian_blur_effect.h b/src/effects/gaussian_blur_effect.h
index 8bf34dc..6c8d8a4 100644
--- a/src/effects/gaussian_blur_effect.h
+++ b/src/effects/gaussian_blur_effect.h
@@ -14,9 +14,9 @@ struct GaussianBlurParams {
 static_assert(sizeof(GaussianBlurParams) == 16,
               "GaussianBlurParams must be 16 bytes");
 
-class GaussianBlurEffect : public Effect {
+class GaussianBlur : public Effect {
  public:
-  GaussianBlurEffect(const GpuContext& ctx,
+  GaussianBlur(const GpuContext& ctx,
                        const std::vector<std::string>& inputs,
                        const std::vector<std::string>& outputs);