fix: clarify continuous ladder wait state

[jackhai9]

Summary

• show direction-specific continuous stop labels for close-long and close-short sessions
• distinguish native-button readiness waiting from the actual one-second inter-round cooldown
• keep the existing timing path unchanged while exposing compact Chinese status feedback

Validation

• npm test (429/429)
• npm run build:binance-orderbook-trade
• npm run check:binance-orderbook-trade
• npm run inspect:binance-orderbook-trade
• git diff --check

Live validation boundary

• no financial action will be performed; post-merge verification will inspect loaded source and non-financial idle UI only