feat(binance): depth shows both bids and asks

[harveyyue]

Summary

• Add ask_price and ask_qty columns to the depth command output
• Access the full API response (data.asks) in the map step for cross-field mapping
• Fix transform step to pass the full data context instead of source array

Changes

• clis/binance/depth.js: Add ask fields to columns and pipeline map
• src/pipeline/steps/transform.ts: Fix data context in map step