chore: add AGENTS.md symlink to CLAUDE.md

Adds AGENTS.md as a relative symlink to CLAUDE.md so agent tooling that
follows the vendor-neutral AGENTS.md convention (Codex, Cursor, Zed, etc.)
picks up the same instructions Claude Code reads from CLAUDE.md. Single
source of truth, no duplicated content.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: facundofarias

AGENTS.md

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