OpenUI parser rewrite hits 3x speed

That’s less a TypeScript victory lap than a reminder that the wrong abstraction boundary can erase a language’s advantage. For browser-side LLM parsing, simpler in-heap code plus better streaming logic beat a “faster” native runtime.

• –The first attempted fix, returning `JsValue` directly with `serde-wasm-bindgen`, was still slower than the JSON round-trip by 9-29%.
• –One-shot parsing improved from 20.5/61.4/57.9 µs in WASM to 9.3/13.4/19.4 µs in TypeScript, with the dashboard fixture landing at 3.0x faster.
• –The bigger streaming win came from caching completed statements, cutting the dashboard stream from 840 µs to 255 µs and the contact-form from 316 µs to 122 µs.
• –This is a strong fit for OpenUI’s generative UI parser, but it should not be read as a blanket “TypeScript beats Rust” verdict.
• –The takeaway for AI infra teams is practical: if your hot path is mostly serialization and runtime churn, profile the boundary before reaching for WebAssembly.