general: T8595: add AGENTS.md

[andamasov]

Adds AGENTS.md (tool-neutral primary instructions) at repo root and a symlink .github/copilot-instructions.md → ../AGENTS.md for Copilot code review compatibility.

Schema rationale and full spec: T8595.

Why this shape: Cursor 0.50+, Claude Code, OpenAI Codex, and Copilot Coding Agent / Chat / CLI read AGENTS.md natively. Copilot code review is the single tool that doesn't (per GitHub's docs) — the symlink is the workaround until community/discussions/174058 lands. Replaces the previous CLAUDE.md-only schema PR for this repo.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on this repository. Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 52f5ac95-c12d-40ab-9851-c8c7ee6c4658

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch T8595-add-agents-md

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch T8595-add-agents-md

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}