Keep private email out of the Honestly export

The Email column exported employees.email, which is the person's
private address. That does not belong in a file sent to an outside
survey provider, least of all as the address invitations go to in the
employer's name.

The column now stays as a placeholder for the work email, which does
not exist in the schema yet and will be added later. It is empty until
then, but keeps its place so the column mapping set up in Honestly does
not have to change once the address arrives. The export no longer
reads employees.email at all, so it cannot end up in another column
by accident either.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

components/reports/ReportsPageClient.tsx

@@ -644,8 +644,9 @@ export function ReportsPageClient(props: ReportsPageClientProps) {
           <div className="rounded border border-border bg-white p-4">
             <h3 className="mb-1 text-xs font-semibold uppercase tracking-wide text-ink-muted">Honestly-Report</h3>
             <p className="mb-1 text-xs text-ink-muted">
-              Teilnehmerliste für die Mitarbeiterbefragung: Personalnummer, E-Mail, Name, Standort und die
+              Teilnehmerliste für die Mitarbeiterbefragung: Personalnummer, Name, Standort und die
               Organisationskette von der eigenen Einheit bis ganz oben. Sprache immer „de“, Rolle immer „Respondee“.
+              Die Spalte „Email“ bleibt leer, bis die Firmen-E-Mail-Adresse erfasst wird.
             </p>
             <p className="mb-2 rounded bg-surface px-2 py-1.5 text-xs font-semibold text-ink-body">Status im Export: {statusExportLabel}</p>
             <div className="flex gap-2">