Desktop app dynamic config of API Port (#40)

* added dynamic configuration of Port in Desktop app
* added dynamic configuration of API_URL to docker deployments.

Now it works with editing only .env file.

docker/.env.prd

@@ -1,10 +1,10 @@
 # Environment variables for Bamort production environment
 
 # API Configuration
+# API_URL is used by the frontend to generate config.json at container startup
+# Change this value and restart containers (no rebuild needed!)
 API_URL=https://bamort-api.trokan.de
-VITE_API_URL=https://bamort-api.trokan.de
-
-# Database Configuration Backend
+API_PORT=8180
 DATABASE_TYPE=mysql
 #DATABASE_URL=bamort:bG4)efozrc@tcp(mariadb:3306)/bamort?charset=utf8mb4&parseTime=True&loc=Local
 
@@ -14,7 +14,7 @@ MARIADB_PASSWORD=bG4)efozrc
 MARIADB_DATABASE=bamort
 MARIADB_USER=bamort
 
-API_PORT=8180
+# Frontend Configuration
 BASE_URL=https://bamort.trokan.de
 TEMPLATES_DIR=./templates
 EXPORT_TEMP_DIR=./export_temp