docs: add AGENTS.md for universal agent guidelines

.gitignore

@@ -13,7 +13,6 @@ coverage.html
 .claude/commands/read-issue.md
 .claude/settings.local.json
 
-CLAUDE.md
 pages/package-lock.json
 scripts/hooks/
 scripts/publish/.env.internal

AGENTS.md

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+# Agent Guidelines for open-code-review
+
+This file provides instructions for AI coding assistants working on this project.
+
+## Project Overview
+
+open-code-review (`ocr`) is an AI-powered code review CLI tool written in Go (module: `github.com/alibaba/open-code-review`).
+
+## Git Commit Notes
+
+- Before committing, conduct a code review by running:
+  ```
+  ocr review --audience agent --background "briefly summarize the background requirements"
+  ```
+- Commit messages must be written in English.
+
+## License Headers
+
+- Every source file (`.go`, `.sh`, `.js`, `.mjs`, `.ts`, `.tsx`) must have an SPDX license header.
+- After creating new files, run `make license-add` to add the header automatically.
+
+## Code Style
+
+- After writing code, run `make check` to format and check the code.
+- `make check` runs: license check, `go mod tidy`, `gofmt -s -w .`, and `go vet`.
+
+## Testing
+
+- Run unit tests with `make test`, not `go test` directly.
+- `make test` sets `LC_ALL=C` to ensure git outputs English messages.
+- When writing or modifying code, add necessary unit tests to maintain coverage. The project enforces a 90% coverage threshold via `make coverage`.
+
+## README
+
+- When modifying README.md, always sync the changes to all localized versions:
+  - README.zh-CN.md
+  - README.ja-JP.md
+  - README.ko-KR.md
+  - README.ru-RU.md

CLAUDE.md

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+See [AGENTS.md](./AGENTS.md) for all project guidelines.