Idle cache 30 min -> 1 h, absolute cap 2 h -> 8 h. Both `lib.mkDefault` so an inventory can set `services.gpg-agent.defaultCacheTtl` without `mkForce`.
Idle cache 30 min -> 1 h, absolute cap 2 h -> 8 h. Both `lib.mkDefault` so an inventory can set `services.gpg-agent.defaultCacheTtl` without `mkForce`.