Implement ActionCable for Live Game Updates #38
Description
Acceptance Criteria
- Stats update without refresh when damaged/healed
- Location changes broadcast to all players in area
- Combat mode triggers UI changes
- Notifications appear and auto-dismiss
Technical Requirements
- Create GameChannel with player-specific streams
- Handle update types: stat_update, location_change, combat_update
- Smooth animations for stat changes (500ms transitions)
- Notification stack in top-right corner