chore: add AGENTS.md → CLAUDE.md symlink for cross-tool agent interop (#16)

Cursor / GitHub Copilot / OpenAI Codex / Zed / Aider read AGENTS.md (the
agents.md cross-tool standard) when a repo is opened standalone — they do not
read CLAUDE.md. A symlink hands those tools this repo's canonical instructions
with zero drift (single source of truth stays CLAUDE.md). Part of the fleet-wide
AGENTS.md interop rollout.

Co-authored-by: cloudingenium-automation[bot] <41898282+cloudingenium-automation[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 3 people

AGENTS.md

@@ -0,0 +1 @@
+CLAUDE.md