AGENTS.md is the canonical agent guide, with CLAUDE.md a thin import

[alunduil]

Summary

Rename CLAUDE.md to AGENTS.md and reduce CLAUDE.md to an @AGENTS.md import plus what is true of Claude Code alone.

Motivation

The file already calls itself an agent guide in its own heading, and its content matches: the tooling inventory, the rule that the Collection+JSON spec beats the test suite, the Haddock and comment conventions, the PVP change classification, the release process, and the don't-touch list. None of it is Claude-specific, yet only Claude Code reads that filename. An agent that isn't Claude Code could shift semantics to make a failing test pass, or ship an upper-bound widening as a major bump, with none of these rules loaded.

Scope

• git mv CLAUDE.md AGENTS.md.
• CLAUDE.md becomes an @AGENTS.md import plus only Claude-Code-specific rules, if any remain.
• Add AGENTS.md to .vale.ini so it lints under the rules CLAUDE.md gets today.

Acceptance criteria

• AGENTS.md carries the library rules
• CLAUDE.md imports it and states nothing another agent also needs
• .vale.ini covers AGENTS.md
• The rule for adding a future tool config is written down
• Pre-commit passes

Gotcha

The heading already reads "collection-json — agent guide", so this is close to a pure rename. The one line to re-examine is the Scope discipline pointer to the issue-work skill: that skill is a host-local Claude Code artifact, not something another agent can invoke, so it either moves to CLAUDE.md or gets restated as the rule it encodes.

Vale styles here are vendored under .vale/styles with no vale sync, so the new path needs adding to .vale.ini by hand.

Additional context

Reference implementation: dungeon-studio/genshin.dungeon.studio#1417, closing #877 there.

• GitHub: add repository custom instructions — Copilot's cloud agent reads AGENTS.md, CLAUDE.md, and .github/copilot-instructions.md.
• Claude Code: AGENTS.md — Claude Code reads only CLAUDE.md, and prescribes the @AGENTS.md import for this case.