Spec drift: kalshi — outcome_side/book_side replacing direction field (May 28 deadline)

[realfishsam]

Summary

Kalshi added outcome_side and book_side fields to Order, Fill, and Trade objects on May 6 2026, and has officially deprecated direction. The direction field will be removed on May 28 2026. Our spec and normalizer still use direction.

Impact

CRITICAL — hard breaking deadline of May 28 2026. After that date, direction will not be present in any Order/Fill/Trade response and all order-direction logic will silently fail.

Details

• New fields: outcome_side (string: "yes" | "no") and book_side (string: "bid" | "ask")
• Deprecated field: direction (string: "buy" | "sell") — removal date May 28 2026
• Affected schemas: Order, Fill, Trade in core/specs/kalshi.yaml
• The semantic mapping: direction: "buy" ≈ buying Yes = outcome_side: "yes", book_side: "bid"

Required Fix

1. Add outcome_side and book_side to the Order, Fill, and Trade schemas in core/specs/kalshi.yaml
2. Mark direction as deprecated in the spec
3. Update the Kalshi normalizer to read outcome_side/book_side with a fallback to direction for any in-flight responses
4. Remove the direction fallback after May 28 2026 (or immediately if deploying post-deadline)