Physics Toy Sandbox

A remixable physics playground - Rube Goldberg machine builder for Jugar.

This crate implements the Physics Toy Sandbox specification with Toyota Way principles:

• Kaizen: Every remix is continuous improvement
• Poka-Yoke: Type-safe material properties (NonZeroU32 for density)
• Jidoka: Engine versioning ensures replay compatibility
• Mieruka: Complexity Thermometer provides visual feedback
• Muda Elimination: No scalar fallback (SIMD support >99%)

Architecture

┌─────────────────────────────────────────────────────────────────┐
│                    PHYSICS TOY SANDBOX                           │
├─────────────────────────────────────────────────────────────────┤
│  Contraption ──► RemixGraph ──► Storage                         │
│       │                                                          │
│       ├── MaterialProperties (Poka-Yoke: NonZeroU32 density)    │
│       ├── PhysicsConfig (versioned)                             │
│       └── SerializedEntity[]                                    │
│                                                                  │
│  ComplexityThermometer (Mieruka) ──► UI Feedback                │
└─────────────────────────────────────────────────────────────────┘