Add spring-boot-microservices-project: config server, Eureka, gateway and three services on Boot 4.1.1 + Spring Cloud 2025.1.3

Product, order and inventory services behind Spring Cloud Gateway (WebMVC), configuration from a Config Server,
discovery with Eureka, a Resilience4j circuit breaker on order -> inventory and Brave tracing. Run as six plain jars;
output/ holds real transcripts (config, registry, requests, trace propagation, circuit breaker, startup race and the
load-balanced RestClient.Builder trap). Dockerfile and docker-compose.yml are included but were not run.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01HhW8LD8r3EigoBaCGrQZx5

output/06-eureka-lb-trap.txt

@@ -0,0 +1,9 @@
+# order-service started with --shop.demo.primary-builder=false (the only RestClient.Builder is the @LoadBalanced one)
+
+--- the log lines that give it away ---
+org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'scopedTarget.eurekaClient': Requested bean is currently in creation: Is there an unresolvable circular reference or an as
+c.n.d.s.t.d.RedirectingEurekaHttpClient  : Request execution error. endpoint=DefaultEndpoint{ serviceUrl='http://localhost:8761/eureka/}, exception=No instances available for localhost
+com.netflix.discovery.DiscoveryClient    : DiscoveryClient_ORDER-SERVICE/order-service:8092 - registration failed Cannot execute request on any known server
+
+--- is instance order-service:8092 in Eureka? ---
+order-service:8092 registered: False