This PR adds an `AGENTS.md` symlink to `.claude/CLAUDE.md` so
Codex-style repository instructions can resolve to the same checked-in
guidance Claude Code already uses.
This keeps the repository's agent-facing instructions in one place
instead of maintaining separate copies for different tools. Previous
Codex runs did not automatically pick up the existing
`.claude/CLAUDE.md` guidance, which caused avoidable drift in PR
formatting and workflow behavior.
