refactor(ping-service): remove CORS configuration from code, restructure modules, and update Gradle dependencies

Migrated CORS settings from code to `application.yaml` for better separation of concerns. Integrated `ping-api` into the new `contracts` module for improved modularity. Updated Gradle scripts and dependencies accordingly to reflect the new project structure.

backend/services/ping/ping-service/src/main/kotlin/at/mocode/ping/PingServiceApplication.kt

@@ -2,33 +2,12 @@ package at.mocode.ping
 
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.runApplication
-import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.EnableAspectJAutoProxy
-import org.springframework.web.servlet.config.annotation.WebMvcConfigurer
 
 @SpringBootApplication
 // Scannt explizit alle Sub-Packages (infrastructure, application, domain)
 @EnableAspectJAutoProxy
-class PingServiceApplication {
-
-    @Bean
-    fun corsConfigurer(): WebMvcConfigurer {
-        return object : WebMvcConfigurer {
-            override fun addCorsMappings(registry: org.springframework.web.servlet.config.annotation.CorsRegistry) {
-                registry.addMapping("/**")
-                    .allowedOriginPatterns("http://localhost:*")
-                    .allowedOrigins("http://localhost:8080",
-                        "http://localhost:8083",
-                        "http://localhost:4000"
-                    )
-                    .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
-                    .allowedHeaders("*")
-                    .allowCredentials(true)
-                    .maxAge(3600)
-            }
-        }
-    }
-}
+class PingServiceApplication
 
 fun main(args: Array<String>) {
     runApplication<PingServiceApplication>(*args)

backend/services/ping/ping-service/src/main/resources/application.yaml

@@ -42,6 +42,17 @@ spring:
         health-check-interval: 10s
         instance-id: ${spring.application.name}-${server.port}-${random.uuid}
 
+# CORS-Konfiguration ausgelagert aus dem Code
+web:
+  cors:
+    mappings:
+      "/**":
+        allowed-origin-patterns: "http://localhost:*,http://127.0.0.1:*"
+        allowed-methods: "GET,POST,PUT,DELETE,OPTIONS"
+        allowed-headers: "*"
+        allow-credentials: true
+        max-age: 3600
+
 management:
   endpoints:
     web: