refactor: update docker images to use custom registry and optimize configurations

Switched container images in `dc-infra.yaml` to a custom Docker registry for better control and consistency across deployments. Added Keycloak with enhanced configurations and updated several container restart policies, memory allocations, and healthcheck settings for improved performance and compatibility.

backend/infrastructure/gateway/src/main/java/org/springframework/boot/data/valkey/autoconfigure/DataValkeyReactiveAutoConfiguration.java

@@ -1,4 +1,4 @@
-package org.springframework.boot.data.redis.autoconfigure;
+package org.springframework.boot.data.valkey.autoconfigure;
 
 import org.springframework.context.annotation.Configuration;
 
@@ -7,5 +7,5 @@ import org.springframework.context.annotation.Configuration;
  * to be present at this location, even though Spring Boot 3.5.9 moved it.
  */
 @Configuration
-public class DataRedisReactiveAutoConfiguration {
+public class DataValkeyReactiveAutoConfiguration {
 }

backend/infrastructure/gateway/src/main/resources/application.yaml

@@ -8,12 +8,12 @@ spring:
     exclude:
       - "org.springframework.cloud.client.loadbalancer.LoadBalancerAutoConfiguration"
 
-  # --- REDIS (für Rate Limiting) ---
+  # --- VALKEY (für Rate Limiting) ---
   data:
-    redis:
-      host: ${SPRING_DATA_REDIS_HOST:localhost}
-      port: ${SPRING_DATA_REDIS_PORT:6379}
-      password: ${SPRING_DATA_REDIS_PASSWORD:redis-password}
+    valkey:
+      host: ${SPRING_DATA_VALKEY_HOST:localhost}
+      port: ${SPRING_DATA_VALKEY_PORT:6379}
+      password: ${SPRING_DATA_VALKEY_PASSWORD:valkey-password}
 
   # --- CONSUL (Service Discovery) ---
   cloud:
@@ -27,7 +27,7 @@ spring:
         # Aber für den Anfang reicht es, wenn wir Consul finden.
 
     gateway:
-      httpclient: {}
+      httpclient: { }
       # Routen sind in GatewayConfig.kt definiert
 
   # --- SECURITY (OAuth2 Resource Server) ---