fix: installer checks containers only; the panel reads signed manifests from the registry when it has none; unsigned-updater nodes are labeled from the panel's manifests; sign node release images; release 0.3.0 [CI]

.woodpecker/gitea-release.yml

@@ -27,6 +27,9 @@ steps:
       ZOT_USERNAME: justme
       ZOT_SECRET:
         from_secret: zot_secret
+      RELEASE_API_URL: https://mo.oeo.one
+      RELEASE_SIGNING_KEY:
+        from_secret: release_signing_key
     commands:
       - bash ci/release-node-images.sh
     depends_on: []