chore: rename CLAUDE.md to AGENTS.md and Justfile to justfile

.github/PULL_REQUEST_TEMPLATE.md

@@ -36,7 +36,7 @@ with the numbers if the change claims a performance effect. State the numbers, n
 - [ ] **Behaviour changed?** If a wrong change here could pass silently, pin it with
       a test whose name is the claim and whose docstring opens `INVARIANT:` and says
       what breaks it. Do **not** write prose about mechanism — there is no page for
-      it. See the "Where a fact goes" section of [`CLAUDE.md`](../CLAUDE.md).
+      it. See the "Where a fact goes" section of [`AGENTS.md`](../AGENTS.md).
 - [ ] **Adding a fact anywhere?** Run the admission check: derivable from
       `faststream_outbox/` → don't write it; enforceable → a test; a user needs it →
       `docs/`; otherwise it does not get written.

CLAUDE.md → AGENTS.md

@@ -1,4 +1,4 @@
-# CLAUDE.md
+# AGENTS.md
 
 This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
 

tests/test_client_contract.py

@@ -22,7 +22,7 @@
 
 The one drift this cannot catch: an in-process test can't manufacture cross-host
 DB-vs-worker clock skew, so the real client's server-side ``make_interval`` clock
-authority stays a documented invariant (CLAUDE.md), not an assertion here.
+authority stays a documented invariant (AGENTS.md), not an assertion here.
 """
 
 import datetime as _dt