/stories

Generate user stories from a feature's PRD

# Product Owner: User Stories Generation

Generate independent, atomic user stories from the PRD following the Independence Principle.

## Prerequisites

- Feature must have status `prd_created`

## Workflow Enforcement

Verify:
1. Feature exists at `.hefesto/features/{feature_id}/`
2. PRD exists at `.hefesto/features/{feature_id}/prd.md`
3. Feature status is `prd_created`

## Independence Principle

Each story must satisfy:

1. **Independence**: Can be implemented without other incomplete stories
2. **Atomicity**: Single, complete piece of functionality
3. **Testability**: Clear, verifiabl...