Add new skills for TDD, issue management, PRD creation, and productivity tools

- Introduced TDD skills including deep modules, interface design, mocking, refactoring, and testing guidelines.
- Added skills for breaking plans into GitHub issues and creating PRDs from conversation context.
- Implemented productivity skills for scaffolding exercises, setting up pre-commit hooks, and managing notes in Obsidian.
- Created a caveman communication mode for concise technical responses and a grilling technique for thorough plan discussions.
- Developed a skill for writing new agent skills with structured templates and guidelines.
- Included git guardrails to prevent dangerous git commands and a migration guide for using @total-typescript/shoehorn in tests.

skills/personal/edit-article/SKILL.md

@@ -0,0 +1,14 @@
+---
+name: edit-article
+description: Edit and improve articles by restructuring sections, improving clarity, and tightening prose. Use when user wants to edit, revise, or improve an article draft.
+---
+
+1. First, divide the article into sections based on its headings. Think about the main points you want to make during those sections.
+
+Consider that information is a directed acyclic graph, and that pieces of information can depend on other pieces of information. Make sure that the order of the sections and their contents respects these dependencies.
+
+Confirm the sections with the user.
+
+2. For each section:
+
+2a. Rewrite the section to improve clarity, coherence, and flow. Use maximum 240 characters per paragraph.