- Add trade logic to MonopolyLogic: isTradeable, validateTrade, applyTrade
- Properties with buildings (or in groups with buildings) cannot be traded
- Validates ownership, cash affordability, and player activity
- Handles two-way cash flows and property ownership transfers
- Add AI trade evaluation to MonopolyAI: evaluateTrade
- Scores offers based on cash delta, asset value, group control changes
- Detects set completions and control crossings (past 50%)
- Vets breaking up completed monopolies
- Applies skill-based thresholds and randomness
- Returns acceptance decision with human-readable reason
- Add trade modal UI to MonopolyGame
- Three-column layout: your properties, give/get lanes, opponent properties
- Drag-and-drop property cards into trade lanes
- Cash steppers for adding/requesting cash
- Opponent tabs to switch counterparty
- Hover cards for detailed property info
- Visual feedback: pulsing hints when offer is empty, accept/reject messages
- "Initiate Trade" button in end-turn menu
