refactor(ci): Rename images to stack-* prefix for clarity

Renamed all Docker images from generic names to stack-* prefix:
- api → stack-api
- web → stack-web
- postgres → stack-postgres
- openbao → stack-openbao
- orchestrator → stack-orchestrator

This prevents confusion with other repositories in the mosaic/
organization on git.mosaicstack.dev.

Registry images:
  git.mosaicstack.dev/mosaic/stack-api
  git.mosaicstack.dev/mosaic/stack-web
  git.mosaicstack.dev/mosaic/stack-postgres
  git.mosaicstack.dev/mosaic/stack-openbao
  git.mosaicstack.dev/mosaic/stack-orchestrator

Local images:
  stack-api:latest
  stack-web:latest
  stack-postgres:latest
  stack-openbao:latest
  stack-orchestrator:latest

Updated files:
- .woodpecker.yml (all build steps + package linking)
- docker-compose.swarm.yml (all image references)
- build-images.sh (local image names)
- deploy-swarm.sh (image validation)

deploy-swarm.sh

@@ -84,7 +84,7 @@ if [ "$IMAGE_TAG" = "local" ]; then
     USE_REGISTRY=false
     echo "🔍 Using local images (IMAGE_TAG=local)"
     IMAGES_MISSING=0
-    for img in mosaic-stack-postgres mosaic-stack-openbao mosaic-stack-api mosaic-stack-orchestrator mosaic-stack-web; do
+    for img in stack-postgres stack-openbao stack-api stack-orchestrator stack-web; do
         if ! docker images --format "{{.Repository}}" | grep -q "^${img}$"; then
             echo "   ⚠️  Missing: $img"
             IMAGES_MISSING=1
@@ -112,11 +112,11 @@ else
     echo "   Tag: $IMAGE_TAG"
     echo ""
     echo "   Images will be pulled from:"
-    echo "   - $REGISTRY/mosaic/postgres:$IMAGE_TAG"
-    echo "   - $REGISTRY/mosaic/openbao:$IMAGE_TAG"
-    echo "   - $REGISTRY/mosaic/api:$IMAGE_TAG"
-    echo "   - $REGISTRY/mosaic/orchestrator:$IMAGE_TAG"
-    echo "   - $REGISTRY/mosaic/web:$IMAGE_TAG"
+    echo "   - $REGISTRY/mosaic/stack-postgres:$IMAGE_TAG"
+    echo "   - $REGISTRY/mosaic/stack-openbao:$IMAGE_TAG"
+    echo "   - $REGISTRY/mosaic/stack-api:$IMAGE_TAG"
+    echo "   - $REGISTRY/mosaic/stack-orchestrator:$IMAGE_TAG"
+    echo "   - $REGISTRY/mosaic/stack-web:$IMAGE_TAG"
     echo ""
     echo "   Note: Ensure you're logged in to the registry:"
     echo "   docker login $REGISTRY"