Store search, security panel, System-AI fix hint and the
approvals payload hint addressed the operator informally while
the rest of the app uses Sie — the panel flagged the break on
every second screen. All DE strings now use the formal address,
and a guard test rejects any future informal form in app_de.arb.
Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>
