Extract story metrics skill from story-writer agent

Overview

Extract the performance metrics calculation logic from story-writer agent into a dedicated skill with bash script. The agent will preload this skill for calculating commit counts, timestamps, duration, and velocity.

Key Files

• plugins/core/agents/story-writer.md - Simplify to preload skill
• plugins/core/skills/story-metrics/SKILL.md - New skill definition (create)
• plugins/core/skills/story-metrics/scripts/calculate.sh - Bash script for metrics calculation (create)

Implementation Steps

1. Create plugins/core/skills/story-metrics/SKILL.md with instructions for using the metrics script
2. Create plugins/core/skills/story-metrics/scripts/calculate.sh that:
   • Takes base branch as argument (default: main)
   • Calculates commit count: git rev-list --count <base>..HEAD
   • Gets first/last commit timestamps
   • Calculates duration in hours
   • Determines velocity unit (hours vs business days)
   • Outputs JSON with all metrics for easy parsing
3. Update plugins/core/agents/story-writer.md:
   • Add skills: [story-metrics] to frontmatter
   • Replace inline bash commands with reference to skill script
   • Keep narrative writing instructions in agent

Considerations

• Script output should be JSON for reliable parsing
• Duration unit logic (hours vs business days) belongs in script
• Story narrative generation stays in agent (requires LLM reasoning)

Final Report

Development completed as planned.