fix(ci): use --network=host for Docker base image builds

Allows build containers to reach npm registries and local registries
on the host network.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

deployment/build-base-images.sh

@@ -60,6 +60,7 @@ build_with_retry() {
 
     for i in $(seq 1 $max); do
         if docker build \
+            --network=host \
             --file "$BASE_DIR/$dockerfile" \
             --tag "$tag" \
             --tag "${tag%:*}:$(date +%Y%m%d)" \