Permissions for runtime user on all objects in schema (including future objects)
Yes. The key word is DEFAULT PRIVILEGES.

ALTER DEFAULT PRIVILEGES FOR ROLE owner_user IN SCHEMA owner 
GRANT SELECT ON TABLES TO runtime;


Grants the specifies privileges for all specified objects created in the future, by the specified role to the other specified role.

I specified the target_role (owner_user) explicitly to avoid ambiguity. Else, quoting the manual:


  If FOR ROLE is omitted, the current role is assumed.


Related:


Grant all on a specific schema in the db to a group role in PostgreSQL
How to manage DEFAULT PRIVILEGES for USERs on a DATABASE vs SCHEMA?


And don't forget access to sequences if you have any serial columns. The first linked answer has instructions.