docs(DOC-1919): add cloud stub for aws-iam-aurora Connect guide (#612)

The Aurora IAM-roles authentication guide in rp-connect-docs#396 carries
tag::single-source[] markers but had no cloud-docs stub, so the guide
only publishes under the standalone Redpanda Connect docs. Since
DOC-1919 targets Cloud customers and postgres_cdc/mysql_cdc are
Cloud-supported, this stub completes the Pattern B single-source.

- Stub at modules/develop/pages/connect/guides/cloud/aws-iam-aurora.adoc
  follows the same shape as sibling stubs aws.adoc and gcp.adoc
- nav.adoc entry added under "Cloud Credentials", between aws and gcp
- whats-new-cloud entry added under June 2026

Companion PR: redpanda-data/rp-connect-docs#396

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: Feediver1

modules/ROOT/nav.adoc

@@ -324,6 +324,7 @@
 **** xref:develop:connect/guides/bloblang/arithmetic.adoc[]
 *** Cloud Credentials
 **** xref:develop:connect/guides/cloud/aws.adoc[]
+**** xref:develop:connect/guides/cloud/aws-iam-aurora.adoc[]
 **** xref:develop:connect/guides/cloud/gcp.adoc[]
 *** xref:develop:connect/guides/cloud/gateway.adoc[]
 *** xref:develop:connect/guides/sync_responses.adoc[]

modules/develop/pages/connect/guides/cloud/aws-iam-aurora.adoc

@@ -0,0 +1,3 @@
+= Authenticate to Amazon Aurora using IAM roles
+:page-aliases: guides:cloud/aws-iam-aurora.adoc
+include::connect:guides:cloud/aws-iam-aurora.adoc[tag=single-source]

modules/get-started/pages/whats-new-cloud.adoc

@@ -8,6 +8,10 @@ This page lists new features added to Redpanda Cloud.
 
 == June 2026
 
+=== Connect to Amazon Aurora with IAM roles
+
+A new guide walks Cloud customers through configuring IAM Roles for Service Accounts (IRSA) so Redpanda Connect pipelines can authenticate to Amazon Aurora without storing static database credentials. The setup uses a two-hop role chain: the Connect pipeline role assumes a customer-owned database connect role in the Aurora account, which generates a short-lived RDS IAM authentication token. Applies to `postgres_cdc`, `pg_stream`, and `mysql_cdc` inputs. See xref:develop:connect/guides/cloud/aws-iam-aurora.adoc[Authenticate to Amazon Aurora using IAM roles].
+
 === Customer-managed default topic settings
 
 You can now set cluster-wide defaults for new topics on BYOC and Dedicated clusters. The xref:reference:properties/cluster-properties.adoc#default_topic_partitions[`default_topic_partitions`], xref:reference:properties/cluster-properties.adoc#log_retention_ms[`log_retention_ms`], and xref:reference:properties/cluster-properties.adoc#retention_bytes[`retention_bytes`] cluster properties are now customer-managed. The default topic retention period (`log_retention_ms`) previously could only be changed by Redpanda support. See xref:manage:cluster-maintenance/config-cluster.adoc[Configure Cluster Properties].