Add 4 practical Claude skills from the @thebrierfox skill library:
Document Processing
- doc2math — Transforms unstructured documents into formal mathematical representations: equations, LaTeX notation, symbolic models, and proof structures.
Development & Code Tools
- ai-identity-persistence-contract — Behavioral fingerprinting and session-continuity contract for AI agents — defines cross-context identity coherence, memory anchors, and drift-detection patterns.
Data & Analysis
- yield-intelligence — Passive income portfolio analysis: live Treasury rates, dividend yields, I-Bond projections, REIT modeling, and AI-powered allocation recommendations.
Business & Marketing
- moatmri — AI disruption pressure analysis for any business — surfaces competitive moat erosion points, replacement risk vectors, and defensibility gaps across business model dimensions.
All four repos contain SKILL.md with proper YAML frontmatter and follow the Claude Skills standard.