Add Growth and Speed Food Types

[dmccoystephenson]

Description

Implement two different types of food items that affect the snake differently.

Tasks

• Create red growth food that increases snake length
• Create blue speed food that temporarily increases snake speed
• Implement different spawn rates (80% growth, 20% speed)
• Add visual distinctions between food types
• Implement speed boost duration timer (5 seconds)

Acceptance Criteria

• Two visually distinct food types appear in the game
• Growth food increases snake length
• Speed food temporarily doubles snake speed for 5 seconds
• Snake returns to normal speed after boost expires
• Food types spawn at correct probability rates