Add AGENTS.md and CLAUDE.md with project rules for AI coding agents

[delock]

Summary

Add AGENTS.md and CLAUDE.md to provide project-specific rules for AI coding agents (OpenCode, Claude Code, etc.) working on the
DeepSpeed codebase.

Motivation

AI coding agents are increasingly used for development tasks. Without project-specific instructions, they often produce PRs that violate DeepSpeed conventions — missing DCO sign-off, using import torch.distributed, making cosmetic formatting changes, or generating code that doesn't match the surrounding style. This file encodes those rules so agents follow them automatically.

What's included

• Commit & CI requirements: DCO sign-off, yapf/flake8 formatting, pre-commit checks, check-torchdist rule, license header for new files.
• Code change discipline: No cosmetic-only changes, remove dead code decisively, consolidate tests, match surrounding code style, write beginner-friendly code, comment the "why" not the "what".
• Tool caveats: Known issue with AI agent edit tools that silently reformat code.

Two identical files are provided (AGENTS.md for OpenCode, CLAUDE.md for Claude Code) with a comment reminding contributors to keep them in sync.

[sfc-gh-truwase]

@delock thanks for the PR. The files seem to be duplicated content. Is this unavoidable?

[delock]

@delock thanks for the PR. The files seem to be duplicated content. Is this unavoidable?

Hi @sfc-gh-truwase, Claude Code and OpenCode use different name for the file. OpenCode suggest duplicate the file and rely on agents to maintain consistency.