I am fighting context switching by

- spending more time upfront working with agent on intent of the change, then design, so agent does not try to work around issues in a way that I don't intend to

- investing in ways in which agent can verify it's own change

- giving access to as much prod telemetry, etc so it can also verify the change post-merge

- obvious stuff, like automated review loops etc

But in the end I still read the "load bearing" parts of the code. Less closely, and I've long ago stopped looking at the tests. It's better for me than couple of months ago.