docs: rewrite CLAUDE.md to point to AGENTS.md as authoritative source (#5138)

.gitignore

@@ -25,7 +25,6 @@ package-lock.json
 .cursor
 .qoder
 .claude
-CLAUDE.md
 .codex
 
 # Qwen Code Configs

CLAUDE.md

@@ -0,0 +1,5 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+**Read [`AGENTS.md`](AGENTS.md) — it is the single source of truth for all coding conventions, build/test commands, code style, commit conventions, PR workflow, and review guidelines. All rules in AGENTS.md apply to Claude Code.**