[Frontend] Add public profile revocation propagation tests

## Problem
Revoking a QR or sharing link in one tab/device may leave an already-open public profile showing data until a manual reload.
## Acceptance criteria
- Public views revalidate on focus and at a documented interval.
- Revocation removes or masks protected fields without exposing the reason.
- Browser caches and service workers cannot resurrect the old profile.
- Tests cover multiple tabs, offline-to-online transition, expiry, and race conditions.

No files, tests, or entry points are named. Start by locating the public profile rendering, revocation handling, and cache or service-worker integration, then identify how frontend tests are organized. Done means meeting every acceptance criterion, including focus and interval revalidation, protected-field masking, cache safety, and coverage for tabs, offline recovery, expiry, and races.

Written by the indexing model from the issue text.