AGENTS.md Fallback for Open-Source Repos

Because Claude Code automatically falls back to reading AGENTS.md if no CLAUDE.md is present, and Codex CLI, Cursor, Continue.dev, Aider, and OpenHands all support AGENTS.md natively, shipping a single well-crafted ./AGENTS.md file eliminates cross-file duplication.

File: ./AGENTS.md

Single cross-tool source of truth (<300 lines, <32 KiB) defining build commands, tech stack versions, directory mapping, and project conventions.