Profiler modules in packages/core/src/profiler/:
- FrameStats: rolling 120-frame buffer tracking FPS, CPU/GPU times, node counts
- GpuTimer: EXT_disjoint_timer_query_webgl2 wrapper for GPU-side timing
- DrawCallCounter: WebGL context proxy counting draw calls per frame
- PhaseTimer: Chrome DevTools Performance panel custom tracks via User Timing API
- HudRenderer: in-canvas overlay with stats text and frame time bar graph
- CaptureStack: per-node profiling with speedscope JSON export
- RenderProfiler: orchestrates all layers with zero cost when disabled
Integration:
- SkiaRenderer.render() instrumented with phase markers for scene, picture
recording/replay, section titles, component labels, selection, rulers, flush
- Node counting and viewport culling tracking in renderNode()
- WebGL2 context passed through for GPU timer and draw call counter
- Shift+P keyboard shortcut to toggle HUD overlay
- toggleProfiler() added to editor store
