http-interface-clients

# Declarative HTTP Interface Clients (Boot 3) Spring Framework 6 supports `@HttpExchange` interfaces, but Boot 3 does not provide Boot 4's `@ImportHttpServices` group auto-registration. Build the client adapter explicitly. ```java @HttpExchange("/orders") interface OrderApiClient { @GetExchange("/{id}") OrderDto get(@PathVariable UUID id); } @Configuration class ClientConfig { @Bean OrderApiClient orderApiClient(RestClient.Builder builder, @Value("${clients.orders.base-url}") String baseUrl) { RestClient client = builder.baseUrl(baseUrl).build(); HttpServiceProxyFactory factory = HttpServiceProxyFactory.builderFor(RestClientAdapter.create(client)).build(); return factory.createClient(OrderApiClient.class); } } ``` Use `WebClientAdapter` for reactive interfaces returning `Mono` or `Flux`. Configure base URLs, timeouts, authentication, and error translation in the client adapter layer rather than in controllers or domain services. Prefer one factory/configurer per external service. ## Gotchas - Agent uses `@ImportHttpServices` - that Boot 4 registration API is not available in Boot 3. - Agent adds `@Component` or an implementation to the interface - register the generated proxy as a bean. - Agent uses `RestClient` for `Mono` or `Flux` - use `WebClientAdapter` for reactive return types. - Agent hard-codes remote hosts in annotations - keep URLs in configuration. - Agent lets transport...