Close the "live trading" cell of the cross-language matrix for WASM.
* examples/wasm/live_trading.html — opens a native browser `WebSocket`
to Binance's public kline stream, feeds every close through RSI(14),
MACD(12,26,9) and Bollinger(20, 2.0) via the WebAssembly bindings, and
flags BUY/SELL candidates when all three indicators agree. Mirrors
the Node and Python live-trading examples in indicator set, signal
logic and symbol/interval validation — the symbol is checked against
`^[A-Za-z0-9]+$` before being spliced into the stream URL, the
interval against the public-API allow-list.
The UI shows live close / RSI / MACD-histogram / Bollinger-band cards,
plus a scrolling log of the last 200 ticks with signal rows highlighted.
Browser-native `WebSocket` means no library dependency. Build the WASM
module once (`wasm-pack build bindings/wasm --target web --release
--features panic-hook`), serve the repository root and open
`examples/wasm/live_trading.html`.
kingchenc