How plan mode sits in front of this

Plan mode sits in front of the entire permission system rather than being a variant of it. While active, nothing that would normally trigger a prompt runs at all, not even once, it is recorded as part of the plan instead.

The practical effect is reviewing an entire proposed change at once, at the end, rather than approving individual pieces of it as they come up one at a time during the investigation.

See Plan mode for the full mechanism, including how read-only tools continue to run normally underneath it so the resulting plan is still grounded in real investigation.

This is not a separate, weaker permission system layered alongside the normal one; it is the same underlying rule, run immediately versus wait for approval, with plan mode simply changing what "wait for approval" means for the duration it is active, batched into one review instead of many.

Turning plan mode off again returns to the ordinary per-action prompt immediately; there is no lingering effect on how permissions behave once you have exited it and moved on to a normal turn.