docs: add CLAUDE.md with codebase structure, workflows, and conventions

[codowave]

Summary

Adds a CLAUDE.md file to guide AI assistants working in this repository. No CLAUDE.md, Cursor rules, or Copilot rules existed previously.

The file covers:

• Repository overview — explains that this is a TransformerLens fork hosting two actively-developed custom projects: biblical_correspondence/ (FastAPI Swedenborg correspondence dictionary app) and research_os/ + research/hypotheses/ (hypothesis-verification CLI), and that custom-project code/comments/commits are written in Japanese.
• Commands — Poetry/make targets for the TransformerLens core (tests, format, mypy, docs), pip-based setup and test invocation for biblical_correspondence, and python -m research_os verify usage. Documents the gotcha that root pyproject.toml pytest addopts leak into subproject test runs (requires -o addopts="" outside the Poetry env — verified by running the tests).
• Architecture — hook-point foundation and unified-config design of transformer_lens; the biblical_correspondence three-state lookup invariant (found / not_found / unavailable, "Codex P1") and verified: false index entry handling; the research_os hypothesis lifecycle (exploration → candidate → verified) and falsification-first verification methodology.
• CI and conventions — checks workflow, formatting tools, lockfile sync, and which parts of the repo are/aren't covered by Poetry/CI.

https://claude.ai/code/session_01C26qdPwYEYhcsL8Au1AJdA

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Generated by Claude Code

[gemini-code-assist]

Code Review

This pull request introduces a new CLAUDE.md file, which serves as a comprehensive developer guide for Claude Code when working in this repository. It details the repository's dual-purpose structure (a TransformerLens fork containing custom projects for biblical correspondence and research OS), lists relevant setup and testing commands, explains the architecture and key invariants of each project, and outlines CI and formatting conventions. There are no review comments, and I have no feedback to provide.

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