refactor: Bundle GPU context into GpuContext struct

- Created GpuContext struct {device, queue, format}
- Updated Effect/PostProcessEffect to take const GpuContext&
- Updated all 19 effect implementations
- Updated MainSequence.init() and LoadTimeline() signatures
- Updated generated timeline files
- Updated all test files
- Added gpu_get_context() accessor and fixture.ctx() helper

Fixes test_mesh.cc compilation error from g_device/g_queue/g_format conflicts.
All targets build successfully.

1 files changed, 3 insertions, 4 deletions

diff --git a/src/gpu/effects/moving_ellipse_effect.cc b/src/gpu/effects/moving_ellipse_effect.cc
index 3b73697..1163215 100644
--- a/src/gpu/effects/moving_ellipse_effect.cc
+++ b/src/gpu/effects/moving_ellipse_effect.cc
@@ -5,15 +5,14 @@
 #include "gpu/gpu.h"
 
 // --- MovingEllipseEffect ---
-MovingEllipseEffect::MovingEllipseEffect(WGPUDevice device, WGPUQueue queue,
-                                         WGPUTextureFormat format)
-    : Effect(device, queue) {
+MovingEllipseEffect::MovingEllipseEffect(const GpuContext& ctx)
+    : Effect(ctx) {
   uniforms_ =
       gpu_create_buffer(device_, sizeof(float) * 6,
                         WGPUBufferUsage_Uniform | WGPUBufferUsage_CopyDst);
   ResourceBinding bindings[] = {{uniforms_, WGPUBufferBindingType_Uniform}};
   pass_ =
-      gpu_create_render_pass(device_, format, ellipse_shader_wgsl, bindings, 1);
+      gpu_create_render_pass(device_, format_, ellipse_shader_wgsl, bindings, 1);
   pass_.vertex_count = 3;
 }
 void MovingEllipseEffect::render(WGPURenderPassEncoder pass, float t, float b,