Update litellm-health contract to mandate executor script

Add 'Executor Script' section:
- Run scripts/litellm-health-check.py from the clone
- Hand-rolled probes not acceptable substitute
- Backend-edge checks use internal IP 192.168.68.116, not public URL
- Docker Stats fetched from CT 116 host (127.0.0.1:9324/metrics)
- Admin Key List requires proper quoting for SSH commands

litellm-health.prose.md

@@ -185,3 +185,19 @@ contracts — read them there. Do not re-add retired names (`gemma-4-12b`, `gpu-
    - GET {{grafana_url}}/api/health → expect 200
 
 10. **Compile and report** — Determine overall_status from individual check results
+
+## Executor Script (2026-09-13)
+
+**Run `scripts/litellm-health-check.py` from the clone.** This script implements all 11
+checks defined above and reports results in a standardized format. Paste its output in
+the status line.
+
+- Hand-rolled probes are **not** an acceptable substitute for the script.
+- Backend-edge checks (steps 2–8) must use `http://192.168.68.116` (internal IP),
+  **not** the public URL `https://litellm.sysloggh.net` (which returns 401 for those paths).
+- Docker Stats (step 10) must be fetched from the CT 116 host itself (`127.0.0.1:9324/metrics`)
+  because the `harness-docker-stats` container binds to localhost on CT 116.
+- Admin Key List (step 8) requires the master key expanded locally before SSH, then embedded
+  in the remote curl command with proper quoting.
+
+Expected output on a healthy fleet: 11/11 passing checks.