feat(sequence): integrate v2 timeline with main loop

- Generate InitializeV2Sequences() in timeline.cc
- Generate RenderV2Timeline() for frame rendering
- Add timeline_v2.h interface header
- Call InitializeV2Sequences() in main.cc
- V2 sequences instantiated at startup
- Ready for v1→v2 rendering switch

All 35 tests passing ✅

handoff(Claude): V2 integration ready, next: switch rendering to v2

1 files changed, 4 insertions, 0 deletions

diff --git a/src/app/main.cc b/src/app/main.cc
index 587c4fc..406c944 100644
--- a/src/app/main.cc
+++ b/src/app/main.cc
@@ -20,6 +20,7 @@
 #include "generated/assets.h" // Include generated asset header
 #include "gpu/demo_effects.h" // For GetDemoDuration()
 #include "gpu/gpu.h"
+#include "generated/timeline_v2.h"
 #include "platform/platform.h"
 #include "util/math.h"
 #include <cmath>
@@ -107,6 +108,9 @@ int main(int argc, char** argv) {
   platform_state = platform_init(fullscreen_enabled, width, height);
   gpu_init(&platform_state);
 
+  // Initialize v2 sequences
+  InitializeV2Sequences(*gpu_get_context(), width, height);
+
   // Load timeline data (visual effects layering)
 #if !defined(DEMO_HEADLESS)
   LoadTimeline(*gpu_get_main_sequence(), *gpu_get_context());