Update server config, SSL handling, and port mapping logic

Refactored `run_server` to accept explicit config and SSL paths. Added dynamic environment-based config loading and stricter SSL path checks for production. Updated `docker-compose.yml` to use environment variable for port mapping and adjusted `config_prod.json` to reflect correct port usage.

backend/config_prod.json

@@ -1,10 +1,10 @@
 {
     "ssl_cert_path": "/app/backend/ssl/mx-aare-test.psi.ch.pem",
     "ssl_key_path": "/app/backend/ssl/mx-aare-test.psi.ch.key",
-    "OPENAPI_URL": "https://backend:8000/openapi.json",
+    "PORT": 1492,
+    "OPENAPI_URL": "https://backend:1492/openapi.json",
     "SCHEMA_PATH": "/app/src/openapi.json",
     "OUTPUT_DIRECTORY": "/app/openapi",
-    "PORT": 8000,
     "SSL_KEY_PATH": "/app/backend/ssl/mx-aare-test.psi.ch.key",
     "SSL_CERT_PATH": "/app/backend/ssl/mx-aare-test.psi.ch.pem"
 }