Fix database URL driver normalization for psycopg2

backend/app/db/database.py

@@ -7,8 +7,17 @@ if settings.DATABASE_URL.startswith("sqlite"):
         connect_args={"check_same_thread": False}
     )
 else:
+    db_url = settings.DATABASE_URL
+    # Normalize PaaS postgres:// or postgresql:// URLs to explicitly use the psycopg2 driver
+    if db_url.startswith("postgres://"):
+        db_url = db_url.replace("postgres://", "postgresql+psycopg2://", 1)
+    elif db_url.startswith("postgresql://"):
+        db_url = db_url.replace("postgresql://", "postgresql+psycopg2://", 1)
+    elif db_url.startswith("postgresql+psycopg://"):
+        db_url = db_url.replace("postgresql+psycopg://", "postgresql+psycopg2://", 1)
+        
     engine = create_engine(
-        settings.DATABASE_URL,
+        db_url,
         pool_pre_ping=True,
         pool_recycle=300,
         pool_size=10,