feat(wasm): Add wasm32-unknown-unknown build target for in-browser client execution

[umran666]

Description

UniqToken's native core is written in Rust (crates/uniqtoken_core). Compiling this core to WebAssembly (wasm-pack / wasm-bindgen) will enable zero-latency, client-side tokenization inside browser web apps and playground visualizers.

Scope of Work

1. Add wasm-bindgen support to crates/uniqtoken_core/Cargo.toml.
2. Export wasm_encode(text) and wasm_decode(ids) entry points.
3. Verify compilation with wasm-pack build --target web.

Getting Started

• Files: crates/uniqtoken_core/src/lib.rs, crates/uniqtoken_core/Cargo.toml