Performance budgets & perf meter overlay #41
Description
Performance budgets & perf meter overlay
Labels: performance, observability, project:newton
Milestone: PROJECT: Newton
Summary
Define per-frame budgets (overlays ≤ 0.8 ms, SAT ≤ 1.5 ms @ 20 bodies, events ≤ 0.2 ms @ 200/min) and add a lightweight perf meter overlay with rolling averages.
Acceptance Criteria
- Budgets documented in code and README
- Perf meter overlay shows current ms/frame per subsystem
- Soft warnings logged when budgets exceeded
Tests (write first)
- perfOverlay.test: overlay presence; basic counters update