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/deprecated/request-refactor-plan/SKILL.md

@@ -0,0 +1,68 @@
+---
+name: request-refactor-plan
+description: Create a detailed refactor plan with tiny commits via user interview, then file it as a GitHub issue. Use when user wants to plan a refactor, create a refactoring RFC, or break a refactor into safe incremental steps.
+---
+
+This skill will be invoked when the user wants to create a refactor request. You should go through the steps below. You may skip steps if you don't consider them necessary.
+
+1. Ask the user for a long, detailed description of the problem they want to solve and any potential ideas for solutions.
+
+2. Explore the repo to verify their assertions and understand the current state of the codebase.
+
+3. Ask whether they have considered other options, and present other options to them.
+
+4. Interview the user about the implementation. Be extremely detailed and thorough.
+
+5. Hammer out the exact scope of the implementation. Work out what you plan to change and what you plan not to change.
+
+6. Look in the codebase to check for test coverage of this area of the codebase. If there is insufficient test coverage, ask the user what their plans for testing are.
+
+7. Break the implementation into a plan of tiny commits. Remember Martin Fowler's advice to "make each refactoring step as small as possible, so that you can always see the program working."
+
+8. Create a GitHub issue with the refactor plan. Use the following template for the issue description:
+
+<refactor-plan-template>
+
+## Problem Statement
+
+The problem that the developer is facing, from the developer's perspective.
+
+## Solution
+
+The solution to the problem, from the developer's perspective.
+
+## Commits
+
+A LONG, detailed implementation plan. Write the plan in plain English, breaking down the implementation into the tiniest commits possible. Each commit should leave the codebase in a working state.
+
+## Decision Document
+
+A list of implementation decisions that were made. This can include:
+
+- The modules that will be built/modified
+- The interfaces of those modules that will be modified
+- Technical clarifications from the developer
+- Architectural decisions
+- Schema changes
+- API contracts
+- Specific interactions
+
+Do NOT include specific file paths or code snippets. They may end up being outdated very quickly.
+
+## Testing Decisions
+
+A list of testing decisions that were made. Include:
+
+- A description of what makes a good test (only test external behavior, not implementation details)
+- Which modules will be tested
+- Prior art for the tests (i.e. similar types of tests in the codebase)
+
+## Out of Scope
+
+A description of the things that are out of scope for this refactor.
+
+## Further Notes (optional)
+
+Any further notes about the refactor.
+
+</refactor-plan-template>