feat: Skill gap analysis — compare expertise against role ladders

[Hrithik-Gavankar]

Summary

Compare your current expertise map (from BRAIN.md) against job postings, role ladders, or career frameworks to identify specific gaps and recommend growth actions.

Motivation

• Engineers often don't know what they're missing for the next level
• Role ladders exist but mapping your work to them is manual and subjective
• This makes promotion conversations data-driven

Proposed Features

• engineer-brain gap-analysis command
• Built-in role ladder templates (IC2 → IC3, IC3 → IC4, IC4 → Staff)
• Custom ladder import (paste your company's ladder)
• Job posting comparison (paste a JD, get gap analysis)
• Actionable recommendations (specific repos/tasks to close each gap)
• Progress tracking (re-run monthly to see gaps closing)

Example Output

## Gap Analysis: You (IC3) → Target (IC4/Senior)

### Met ✅
- Technical depth in primary domain (10+ repos, strong expertise)
- Code quality & testing (consistent test coverage, security focus)
- Cross-team collaboration (contributions to 5+ repos)

### Gaps 🔴
- System design ownership: No design docs authored (IC4 expects 2+/year)
- Mentorship: No evidence of mentoring juniors
- Performance optimization: Listed as growth goal but 0 perf: commits

### Recommended Actions
1. Author a design doc for the next medium feature
2. Pick up a perf: task — profile the API hot path
3. Offer to onboard the next new team member