GET /api/geschichten shipped every author's AppUser email to all readers via
GeschichteSummary.AuthorSummary — contradicting the documented rule that
author projections never expose email or group memberships. The frontend
only used it as a display-name fallback; it now falls back to [Unbekannt],
matching the server-side rule in GeschichteService.toView.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>