release: add docs/architecture/10-observability-and-ops.md

docs/architecture/10-observability-and-ops.md

@@ -117,7 +117,7 @@ flowchart TD
 
 ### 2.1 The measured live payload
 
-Probed live on 2026-09-25 against `https://satquery-backend-m4yv.onrender.com/api/health`
+Probed live on 2026-09-25 against `https://<backend-host>/api/health`
 (`release/repo/docs/DEPLOYMENT.md` §2; `release/CURRENT_RELEASE_STATE.md` §1):
 
 ```json
@@ -131,7 +131,7 @@ Probed live on 2026-09-25 against `https://satquery-backend-m4yv.onrender.com/ap
 The exact command recorded elsewhere in the project's evidence register is:
 
 ```bash
-curl --noproxy '*' https://satquery-backend-m4yv.onrender.com/api/health
+curl --noproxy '*' https://<backend-host>/api/health
 ```
 
 (`docs/FINAL_DELIVERY_REPORT.md` §4, cited in `release/repo/docs/architecture/02-deployment-topology.md` §7.1.)
@@ -1781,7 +1781,7 @@ the tunnel is the live transport and the forwarded-port path is dead for a priva
 repo); the tunnel is the live transport."*).
 
 ```bash
-curl --noproxy '*' https://satquery-backend-m4yv.onrender.com/api/health
+curl --noproxy '*' https://<backend-host>/api/health
 ```
 
 Read `tunnel.agent_connected`. `true` means an agent has polled within the last 60 seconds