Add CLAUDE.md development guide for VAFT

[Copilot]

Documents the VAFT codebase for developers: setup, testing, structure, dependencies, and a catalogued audit of known technical debt.

Contents

• Build & Install — pip install, editable dev install, pyproject.toml / setuptools notes
• Testing — pytest test/, external dependencies (HSDS server, MySQL)
• Code Style — black + flake8, no config files, sparse type hints
• Project Structure — annotated directory tree covering all subpackages
• Key Dependencies — table mapping packages to their roles
• Database Connectivity — HSDS endpoint config, MySQL encrypted credential setup

Known Issues Catalogued

Category	Location
SQL injection via f-string queries	database/raw.py
Missing import re	code/efit.py
Resource leaks (no try/finally)	database/raw.py
Inconsistent return types	database/ods.py
~374 print() instead of logging	codebase-wide
Wildcard imports, no __all__	__init__.py files
Hardcoded machine constants & paths	magnetics.py, raw.py, workflows
Dead/deprecated code in git	test/old_codeset.py, code/efit.sav
Empty stub modules	code/chease.py, code/gpec.py
Unguarded division by zero	equilibrium/profile calculations
No CI, pre-commit hooks, or mocking infrastructure	—

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