Enhance member deletion and implement template-based email system

- Add Keycloak user deletion to member removal process
- Implement Handlebars email templates for verification, password reset, and dues reminders
- Improve JWT secret configuration with multiple fallbacks
- Add getMemberById function and enhance error handling
- Update Dockerfile to include email templates in production build

Dockerfile

@@ -17,6 +17,7 @@ RUN npm prune
 FROM base as production
 ENV PORT=$PORT
 COPY --from=build /app/.output /app/.output
+COPY --from=build /app/server/templates /app/server/templates
 
 # Copy debug entrypoint script
 COPY docker-entrypoint-debug.sh /usr/local/bin/