Streamline curve linear wasm hot path

[ShanonJackson]

Summary

• pre-encode curve deltas into a Uint32Array for the wasm encoder to avoid JS string building work
• rewrite the Rust formatter to consume scaled integers directly with a digit lookup table for faster output generation
• streamline the JS delta packing and wasm writer to drop redundant rounding/division work and branch checks, pushing the wasm hot path further past the JS fallback

Testing

• bun test src/utils/path/curve.spec.ts
• CURVE_LINEAR_WASM=crates/curve-linear/target/wasm32-unknown-unknown/release/curve_linear.wasm bun test src/utils/path/curve.spec.ts

---

https://chatgpt.com/codex/tasks/task_e_68f84ca0b98883269d30d3bbbb43e08a