chore(python): release 2.1.1

2.1.0 was tagged but never published. This release carries the
deep-health 503 handling, the restored issue_token aliases, the rotation
grace deadline, and agent-id path encoding.

Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq

elydora/_version.py

@@ -1,3 +1,3 @@
 """Canonical Elydora package version."""
 
-__version__ = "2.1.0"
+__version__ = "2.1.1"