feat: create a new script to mirror dynamic plugin OCI artifacts for airgapped deployments

.gitignore

@@ -44,4 +44,7 @@ rhdh-operator-*.yaml
 rhdh-disconnected-install/
 rhdh-disconnected-install.Dockerfile
 
-.oc-mirror.log
+.oc-mirror.log
+
+# from mirror-plugins.sh script
+rhdh-plugin-mirroring-summary.txt

.rhdh/docs/mirror-dynamic-plugins.adoc

@@ -0,0 +1,58 @@
+== Mirroring Red Hat Developer Hub Dynamic Plugins for Disconnected Environments
+
+Red Hat Developer Hub (RHDH) uses dynamic plugins that are distributed as OCI (Open Container Initiative) artifacts. In disconnected or restricted environments, these plugin artifacts must be mirrored to a registry accessible by your cluster.
+
+This guide explains how to use the link:./../scripts/mirror-plugins.sh[mirror-plugins.sh] script to mirror dynamic plugin OCI artifacts for deployments in restricted environments.
+
+=== Prerequisites
+
+The following tools are required to run the mirroring script:
+
+* `skopeo >= 1.20` - For multi-arch image operations and manifest conversion. See link:https://github.com/containers/skopeo/blob/main/install.md[Installing Skopeo].
+* `tar >= 1.35` - GNU tar for extracting image layers.
+* `jq >= 1.7` - For JSON parsing and manipulation. See link:https://jqlang.github.io/jq/download/[Download jq].
+* `podman >= 5.6` - For building catalog index images. See link:https://podman.io/docs/installation[Podman Installation Instructions].
+
+=== Procedures
+
+[#_mirroring_all_plugins_from_catalog_index]
+==== Mirroring all plugins from a catalog index (Partially disconnected environment)
+
+. Authenticate to both the source registry (`podman login quay.io`) and your target registry. For more information, see link:https://access.redhat.com/articles/RegistryAuthentication[Red Hat Container Registry Authentication].
+
+. Run the mirroring script with the catalog index (replace `1.9` with your desired RHDH version):
++
+[source,console]
+----
+bash mirror-plugins.sh \
+    --plugin-index oci://quay.io/rhdh/plugin-catalog-index:1.9 \
+    --to-registry registry.example.com
+----
+
+[#_fully_disconnected_workflow]
+==== Mirroring to a fully disconnected environment
+
+Two-phase process: export plugins to disk from a connected host, transfer to restricted network, then import. Authenticate to registries as needed (`podman login quay.io` for export, `podman login <your-registry>` for import). For more information, see link:https://access.redhat.com/articles/RegistryAuthentication[Red Hat Container Registry Authentication].
+
+*Phase 1: Export plugins (Connected Host)*
+
+Export all plugins to a local directory:
+
+[source,console]
+----
+bash mirror-plugins.sh \
+    --plugin-index oci://quay.io/rhdh/plugin-catalog-index:1.9 \
+    --to-dir /tmp/rhdh-plugins
+----
+
+*Phase 2: Import plugins (Restricted Network Environment)*
+
+Import and push the plugins to your internal registry:
+
+[source,console]
+----
+bash mirror-plugins.sh \
+    --from-dir /tmp/rhdh-plugins \
+    --to-registry internal-registry.example.com
+----
+