feat: add Berlin timezone support to containers

- Add tzdata package to Dockerfile runner stage
- Set TZ=Europe/Berlin in docker-compose.yml for both trading-bot and postgres
- All container timestamps now show CET instead of UTC
- User-friendly log times matching local time

Files changed:
- Dockerfile: Added tzdata to runner stage
- docker-compose.yml: Added TZ environment variable

docker-compose.yml

@@ -17,6 +17,9 @@ services:
     ports:
       - "3001:3000"
     environment:
+      # Timezone
+      TZ: Europe/Berlin
+      
       # Node environment
       NODE_ENV: production
       PORT: 3000
@@ -96,6 +99,7 @@ services:
     ports:
       - "5432:5432"
     environment:
+      TZ: Europe/Berlin
       POSTGRES_DB: trading_bot_v4
       POSTGRES_USER: postgres
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}