/prd

Create a Product Requirements Document (PRD) for a feature

# Product Owner: PRD Creation

Generate a comprehensive Product Requirements Document following the Single Source of Truth principle.

## Prerequisites

- Feature must exist with status `created`

## Workflow Enforcement

Verify:
1. Feature exists at `.hefesto/features/{feature_id}/feature.json`
2. Feature status is `created`

If not met, show error with correct command.

## Process

### Phase 1: Feature Validation

1. Read `.hefesto/features/{feature_id}/feature.json`
2. Verify status is `created`
3. Load the original request and description

### Phase 2: Overlap Analysis (Mandatory)

1. R...