test: model live cancel dialog scenarios

[jackhai9]

Summary

• add explicit live capture contracts for native cancel-dialog cancel and confirm paths
• decouple one-order smoke capacity evidence from three-level order-scale planning
• keep existing no-orders baselines compatible and document scenario semantics

Validation

• npm test (338 passed)
• npm run test:ui (51 passed)
• npm run check:binance-orderbook-trade
• existing no-orders capture summary and baseline comparison
• git diff --check