[SIMPL-30787] Document container-cluster configuration inputs

Add the cluster-configuration input reference the guide was missing: which inputs are mandatory, conditional or optional in each setup, a reusable minimum input set, and worked examples expressed in the format each setup already uses. No configuration schema or key naming is prescribed.

Retitle the subject sections so they no longer carry one story's AC numbering, and add a traceability section mapping SIMPL-30787 and SIMPL-30451 acceptance criteria onto them.

Changelog: added

yaml/tightly-coupled/values-run-launcher.yaml

@@ -13,8 +13,8 @@ dagster:
     config:
       k8sRunLauncher:
         # Namespace the run pods land in. Must be a namespace whose NetworkPolicy
-        # permits egress to Postgres, object storage and Vault - see AC1
-        # prerequisites in the user guide.
+        # permits egress to Postgres, object storage and Vault - see the
+        # prerequisites in section 2.3 of the user guide.
         jobNamespace: dagster
 
         # Surfaces step failures as pod failures so kubectl and Dagster agree.