chore(semantic): remediate backend core contracts

backend/src/core/database.py

@@ -364,8 +364,9 @@ def get_tasks_db():
 # @TIER: STANDARD
 # @PURPOSE: Dependency for getting an authentication database session.
 # @PRE: AuthSessionLocal is initialized.
-# @POST:    Session is closed after use.
-# @RETURN:  Generator[Session, None, None]
+# @POST: Session is closed after use.
+# @DATA_CONTRACT: None -> Output[sqlalchemy.orm.Session]
+# @RETURN: Generator[Session, None, None]
 def get_auth_db():
     with belief_scope("get_auth_db"):
         db = AuthSessionLocal()