Current topic: "Applying Fixes to correct PR Branch"
Topic summary: I've confirmed that `origin/master` is clean and the PR branch is `fix/issue-81-email-validation`. I will now apply the review fixes surgically to this branch. I'll start by making the Sentry metadata properties internal in `ServiceBookApplication.kt`, then update the ViewModel, Settings screen, and tests. This avoids the merge conflicts I saw earlier by focusing only on the specific changes requested in the review.

Strategic Intent: Apply review fixes to the correct PR branch fix/issue-81-email-validation.