feat: add email-server-worker with clean template architecture

Add new email-server-worker project implementing a self-scheduling background worker pattern with HTTP monitoring. Removed all business-specific code from copied source, creating a clean, reusable template.

Key features:
- Self-scheduling worker loop with configurable interval
- Graceful shutdown support (Docker-compatible)
- Prometheus metrics collection
- Health check endpoints (/healthcheck, /metrics, /ping)
- Example worker template for easy customization
- Comprehensive architecture documentation in CLAUDE.md

The worker is now ready for email server implementation with no external dependencies on Evolution/MSSQL/ElasticSearch.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

email-server-worker/build-image.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+if [ "$1" == "" ] ; then
+    printf "\nDocker image version not set - please specify the version to build"
+    printf "\n\nSyntax:\n\n    build-image.sh 1.0.0\n\n"
+    exit 1
+fi
+
+read -p "BUILD: Push new image to registry [y/n]? " -n 1 -r
+echo    # (optional) move to a new line
+
+PUSH_IMAGE_TO_REPO="$REPLY"
+
+printf "\nBUILD START ...\n\n"
+
+REGISTRY_URL=registry.ngit.hr
+IMAGE_NAME=evo-open-table-sync-svc
+IMAGE_VERSION=$1
+
+IMAGE_TAG=$REGISTRY_URL/ngit/$IMAGE_NAME:$IMAGE_VERSION
+
+docker build . -t $IMAGE_TAG
+
+# if [[ "$PUSH_IMAGE_TO_REPO" =~ ^[Yy]$ ]]
+# then
+#     printf "\nPushing image ...\n\n"
+#     docker push $IMAGE_TAG
+# fi
+
+printf "\nBUILD DONE!\n\n"