Re-implement Countdown Creation and Controls

[Splinter714]

Overview

Re-implement countdown creation, controls, and card functionality that was lost during the major refactor.

Current State

• Countdown cards exist but lack proper creation interface
• Missing countdown-specific controls and interactions
• Need to restore full countdown management functionality

Requirements

• Implement countdown creation interface
• Add countdown-specific controls (start, pause, reset, increment/decrement)
• Design countdown card layouts for compact and expanded views
• Add countdown timer functionality
• Implement countdown editing capabilities
• Add proper countdown state management

Reference

• Check for creation interface
• Check for card implementation
• Follow project organization rules for component placement

Priority

High - Countdowns are core GM functionality

[Splinter714]

Postponed indefinitely - focusing on core gameplay features first.