authelia: extend session inactivity timeout to 2h

Inactivity was 5m which caused logouts while working in VS Code
(no new page loads). Bumped inactivity to 2h, expiration to 12h.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/authelia.nix

@@ -90,8 +90,8 @@ in
             domain = "nordhammer.it";
             authelia_url = "https://auth.nordhammer.it";
           }];
-          expiration = "1h";
-          inactivity = "5m";
+          expiration = "12h";
+          inactivity = "2h";
         };
 
         storage.local.path = "/var/lib/authelia-main/db.sqlite3";