Subdirectory Override Hierarchy in Codex CLI and Claude Code

Both Codex CLI and Claude Code load configuration files hierarchically from the project root down to the working directory, where nearer subdirectory rules override higher-level rules. Use subdirectory AGENTS.md or CLAUDE.md files for legacy packages with different build tools.

File: ./packages/legacy-sdk/AGENTS.md

- Override: This package targets Node 18 CommonJS and builds via 'npm run build:cjs' (do not use root pnpm turbo commands here).