woodpecker: add mediamark-ci service account

Give the mediamark image-build pipeline its own ServiceAccount so the
docker step can push to the trusted in-cluster registry, mirroring
arrproxy-ci.

apps/base/woodpecker/kustomization.yaml

@@ -11,6 +11,7 @@ resources:
   - serviceaccount_autobackup_operator_ci.yaml
   - serviceaccount_ghp.yaml
   - serviceaccount_kea_operator_ci.yaml
+  - serviceaccount_mediamark_ci.yaml
   - serviceaccount_plugin_docker_buildx.yaml
   - serviceaccount_jellyfin_ha_src.yaml
   - serviceaccount_terraform_artifactapi.yaml

apps/base/woodpecker/serviceaccount_mediamark_ci.yaml

@@ -0,0 +1,6 @@
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: mediamark-ci
+  namespace: woodpecker