Current topic: "Updating Setup Screen UX"
Topic summary: I have created the `PrivacyPolicyDialog` component. Now I am modifying `AppNavGraph.kt` to replace the inline `ExpandablePrivacyDisclosure` with a `TextButton` that opens the new dialog. I'm adding the necessary state and imports to support this UX change.

Strategic Intent: Updating the Setup screen in `AppNavGraph.kt` to use the new `PrivacyPolicyDialog` popup.