fix(deploy): Datenbank-Passwort per PGPASSWORD statt in der Verbindungs-URL

Passwörter mit / + = @ (z. B. aus openssl rand -base64) machten DATABASE_URL ungültig
("TypeError: Invalid URL", api und worker im Neustart-Loop). Lokal mit Passwort "Ab/cd+ef=gh9" geprüft.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

deploy/docker-compose.standalone.yml

@@ -21,7 +21,9 @@ x-backend: &backend
   network_mode: host
   env_file: ${ENV_FILE:-.env}
   environment:
-    DATABASE_URL: postgres://atm:${POSTGRES_PASSWORD}@127.0.0.1:5432/atm
+    # Password via PGPASSWORD (read by the PostgreSQL driver): any character works; in the URL "/", "+" or "@" break it.
+    DATABASE_URL: postgres://atm@127.0.0.1:5432/atm
+    PGPASSWORD: ${POSTGRES_PASSWORD}
     HTTP_PROXY: ${HTTP_PROXY:-}
     HTTPS_PROXY: ${HTTPS_PROXY:-}
     NO_PROXY: ${NO_PROXY:-},localhost,127.0.0.1