Add .claude/CLAUDE.md index

[thorwhalen]

Summary

• Adds a concise .claude/CLAUDE.md (module map, verified test/lint commands matching CI's actual doctest flags, the DFLT_MASKING_INPUT secrets-echo gotcha and pointers to related open issues, dependents) per the dev-skills-workflow "CLAUDE.md as the map" convention. Repo had no CLAUDE.md.
• Does not touch open PR chore: remove vestigial setup.cfg, add [tool.wads.ci], migrate CI to the stub #22 (CI-stub migration, blocked on manual-task: hosted CI stuck at action_required on doctor/setup-cfg-and-wads-ci (PR #22) #23) — this branch is off current master, still on the inline CI workflow.

Test plan

• pytest config2py --doctest-modules -o doctest_optionflags='ELLIPSIS IGNORE_EXCEPTION_DETAIL' -q run locally, matching CI's actual flags (132 passed, 4 skipped)
• ruff check . clean
• Docs-only change; hosted CI must be green before merge

🤖 Generated with Claude Code

https://claude.ai/code/session_011HSBVhDjRU4apSLcRkavv9