Add CLAUDE.md for AI-assisted development

[bakerboy448]

Summary

• Adds .claude/CLAUDE.md with project conventions for AI-assisted development tools
• Covers project structure, dev setup, coding standards (ruff config), and PR workflow
• Generic content only — no infrastructure-specific references

Details

This file helps AI coding assistants (Claude Code, Copilot, Cursor, etc.) understand the project's conventions:

• Python 3.10+, setuptools + pyproject.toml
• Ruff linting (line-length=130 per ruff.toml)
• Module structure (modules/, modules/core/, scripts/)
• PRs target develop branch

Test plan

• File contains no sensitive or infrastructure-specific content
• Conventions match existing project standards