refactor: standardize environment variable naming and add PING_SERVICE_URL configuration

Aligned environment variable naming across backend and infrastructure files for improved consistency (e.g., `SPRING_CLOUD_CONSUL` and `SPRING_SECURITY_OAUTH2_RESOURCESERVER`). Introduced `PING_SERVICE_URL` to support dynamic Ping-Service routing. Updated Docker Compose health checks, profiles, and memory settings for scalability and stability.

dc-ops.yaml

@@ -5,11 +5,24 @@ services:
   # 4. OPS & TOOLS (Monitoring & Admin)
   # ==========================================
 
+  # --- EMAIL TESTING: Mailpit ---
+  mailpit:
+    image: "${MAILPIT_IMAGE:-axllent/mailpit:v1.29}"
+    container_name: "${PROJECT_NAME:-meldestelle}-mailpit"
+    restart: unless-stopped
+    profiles: [ "dev-tools", "all" ]
+    ports:
+      - "${MAILPIT_WEB_PORT:-8025:8025}" # Web UI
+      - "${MAILPIT_SMTP_PORT:-1025:1025}" # SMTP Port
+    networks:
+      meldestelle-network:
+
   # --- DATENBANK-MANAGEMENT-TOOL: pgAdmin4 ---
   pgadmin:
     image: "${PGADMIN_IMAGE:-dpage/pgadmin4:8}"
     container_name: "${PROJECT_NAME:-meldestelle}-pgadmin"
-    restart: no
+    restart: unless-stopped
+    profiles: [ "tools", "all" ]
     ports:
       - "${PGADMIN_PORT:-8888:80}"
     environment:
@@ -17,7 +30,6 @@ services:
       PGADMIN_DEFAULT_PASSWORD: "${PGADMIN_PASSWORD:-pgadmin}"
     volumes:
       - "pgadmin-data:/var/lib/pgadmin"
-    profiles: [ "tools", "all" ]
     networks:
       meldestelle-network:
         aliases:
@@ -27,7 +39,8 @@ services:
   postgres-exporter:
     image: "${POSTGRES_EXPORTER_IMAGE:-prometheuscommunity/postgres-exporter:v0.18.0}"
     container_name: "${PROJECT_NAME:-meldestelle}-postgres-exporter"
-    restart: no
+    restart: unless-stopped
+    profiles: [ "ops", "all" ]
     environment:
       DATA_SOURCE_NAME: "postgresql://${POSTGRES_USER:-pg-user}:${POSTGRES_PASSWORD:-pg-password}@postgres:5432/${POSTGRES_DB:-pg-meldestelle-db}?sslmode=disable"
     depends_on:
@@ -37,7 +50,6 @@ services:
       meldestelle-network:
         aliases:
           - "postgres-exporter"
-    profiles: [ "ops", "all" ]
 
   # --- MONITORING: Alertmanager ---
   alertmanager: