Hide pickup cell value for past days in directors forecast worksheet

Past dates already excluded from pickup calculation; suppress display to
avoid giving the impression the stored override is still active.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/pages/DirectorsForecast.tsx

@@ -228,7 +228,7 @@ function WorksheetTab({ year, month }: { year: number; month: number }) {
                         onChange={e => setOvr(day.date, 'pickup_rooms', e.target.value)}
                         className="df-cell-input" />
                     ) : (
-                      <span className="num">{parseInt(ovr.pickup_rooms || '0') || '—'}</span>
+                      <span className="num">{day.is_past ? '—' : (parseInt(ovr.pickup_rooms || '0') || '—')}</span>
                     )}
                   </td>
                   <td className="num df-bold">{c.total}</td>