fix(ci): redirect docker-buildx to private registry

- Use REGISTRY_HOSTPORT for registry (not docker.io or ghcr.io)
- Use REGISTRY_USERNAME/REGISTRY_PASSWORD for auth
- Fix repo path to not include full URL or username prefix

.woodpecker-base.yml

@@ -10,15 +10,16 @@ steps:
   - name: build-base-image
     image: woodpeckerci/plugin-docker-buildx:5.0.0
     settings:
-      registry: ghcr.io
-      repo: ghcr.io/traceworks2023/nxtgauge-rust-base
+      registry:
+        from_secret: REGISTRY_HOSTPORT
+      repo: nxtgauge-rust-base
       context: .
       dockerfile: Dockerfile.base
       tags:
         - latest
         - ${CI_COMMIT_SHA}
       username:
-        from_secret: GHCR_USERNAME
+        from_secret: REGISTRY_USERNAME
       password:
-        from_secret: GHCR_TOKEN
+        from_secret: REGISTRY_PASSWORD
       platforms: linux/amd64

.woodpecker-dockerhub.yml

@@ -87,8 +87,9 @@ steps:
   - name: build-docker
     image: woodpeckerci/plugin-docker-buildx:5.0.0
     settings:
-      registry: docker.io
-      repo: your-dockerhub-username/nxtgauge-rust-${SERVICE}
+      registry:
+        from_secret: REGISTRY_HOSTPORT
+      repo: nxtgauge-rust-${SERVICE}
       dockerfile: Dockerfile.binary
       build_args:
         - SERVICE_NAME=${SERVICE}
@@ -96,7 +97,7 @@ steps:
         - ${CI_COMMIT_SHA}
         - latest
       username:
-        from_secret: DOCKERHUB_USERNAME
+        from_secret: REGISTRY_USERNAME
       password:
-        from_secret: DOCKERHUB_TOKEN
+        from_secret: REGISTRY_PASSWORD
       platforms: linux/amd64