add initial implementation of auth gateway with models, routes, and session management

containers/auth-gateway/auth_gateway/services/totp_service.py

@@ -0,0 +1,9 @@
+import pyotp
+
+
+def verify_totp(secret: str, token: str) -> bool:
+    normalized_secret = secret.strip()
+    normalized_token = token.strip().replace(" ", "")
+    if not normalized_secret or not normalized_token:
+        return False
+    return pyotp.TOTP(normalized_secret).verify(normalized_token, valid_window=1)