fix: GPU table correction + OpenProse v0.15 alignment + self-heal rules 7-9

- hello-world: Ensures -> Maintains (v0.15.0 rename).
- zulip-mention-reliability: fold Success Criteria into Maintains postconditions.
- litellm-self-heal: swap gemma/qwen GPU hosts to match actual deployment;
  add Strix Halo 64GB UMA detail; add Rules 7 (roster stuck), 8 (agent keys
  invalid/401), 9 (stale Redis active counter).

hello-world.prose.md

@@ -10,6 +10,6 @@ description: A simple hello world contract to test OpenProse on pi
 ## Returns
 - greeting: string — The generated greeting message
 
-## Ensures
+## Maintains
 - The greeting includes the provided name
 - The greeting is friendly and warm