Demote dcRedirectionPolicy to optional in forwarding step

Nexus forwarding is on by default (enableNamespaceNotActiveAutoForwarding).
dcRedirectionPolicy is an optional client-API convenience, not a requirement
(default noop; not mandated by the multi-cluster docs).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: stephanos

docs/production-deployment/self-hosted-guide/temporal-nexus.mdx

@@ -116,21 +116,12 @@ target an external URL (`--target-url`), which is experimental and not covered h
    [Nexus Endpoint registry](/nexus/registry) isn't replicated across Clusters.
    Create the same Endpoints (same target Namespace and Task Queue) on each Cluster.
 
-4. **Enable cross-Cluster forwarding.** Two independent settings apply:
-
-   - **Nexus requests and callbacks** are forwarded by
-     `system.enableNamespaceNotActiveAutoForwarding` (per-Namespace dynamic config,
-     defaults to `true`). Make sure it isn't turned off for the Namespace.
-
-   - **Workflow and Activity client APIs** (so callers and clients reach the active
-     Cluster from either side) are forwarded by the server's
-     [`dcRedirectionPolicy`](/references/configuration#dcredirectionpolicy) in static
-     config. It defaults to no redirection, so set it to `all-apis-forwarding`:
-
-     ```yaml
-     dcRedirectionPolicy:
-       policy: "all-apis-forwarding"
-     ```
+4. **Cross-Cluster forwarding.** Nexus request and callback forwarding is on by
+   default via `system.enableNamespaceNotActiveAutoForwarding` (per-Namespace
+   dynamic config); just don't disable it. Optionally, set the server's
+   [`dcRedirectionPolicy`](/references/configuration#dcredirectionpolicy) to
+   `all-apis-forwarding` so Workflow and Activity client APIs also forward to the
+   active Cluster when a client connects to a standby.
 
 ### What to expect on failover