Module fallback 

Fallback chain configuration for agent fault tolerance.

This module defines the FallbackConfig structure that controls how Ralph handles agent failures. It supports:

• Agent-level fallback (try different agents)
• Provider-level fallback (try different models within same agent)
• Exponential backoff with cycling

Structs

FallbackConfig

Agent chain configuration for preferred agents and fallback switching.

Enums

AgentRole

Agent role (developer, reviewer, or commit).