add latest -> previous step

.gitea/workflows/docker-build.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - main
+  workflow_dispatch:
 
 env:
   IMAGE: code.aneur.in/cloud/webfetch-mcpo-docker
@@ -22,12 +23,20 @@ jobs:
         uses: docker/login-action@v3
         with:
           registry: code.aneur.in
-          username: ${{ secrets.PACKAGE_REGISTRY_USER }}
+          username: ${{ gitea.actor }}
-          password: ${{ secrets.PACKAGE_REGISTRY_TOKEN }}
+          password: ${{ secrets.BUILD_API_TOKEN }}
+
+      - name: Promote current "latest" to "previous"
+        run: |
+          if docker buildx imagetools inspect "$IMAGE:latest" >/dev/null 2>&1; then
+            docker buildx imagetools create -t "$IMAGE:previous" "$IMAGE:latest"
+          else
+            echo "No existing :latest to promote; skipping."
+          fi
 
       - name: Build and push
         uses: docker/build-push-action@v5
         with:
           context: .
           push: true
-          tags: ${{ env.IMAGE }}:latest
+          tags: code.aneur.in/${{ gitea.repository }}:latest