The WASM binding had no tests; CI only checked that artefacts existed.
Adds a wasm-bindgen-test suite covering SMA reference values, EMA
batch==streaming equivalence, RSI pure-uptrend behaviour, fallible
constructors returning JsError, and the unequal-length batch guards from
B3. Wires wasm-pack test --node into the CI wasm job. The suite
type-checks on the host; it executes under wasm-pack in CI (the local
environment is a non-rustup Rust install without the wasm32 target).
kingchenc
8192e576cf