fix(welcome,store): sticky flow-completed tick, carousel position text

- the 'start a saved flow' checklist tick no longer unticks once
  the flow.completed event scrolls out of the 100-event window —
  a local sticky marker keeps it honest to its wording
- the Today carousel shows 'n/m' next to the 6-px dots so the
  position is readable without aiming at them

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/pages/store.dart

@@ -3552,6 +3552,20 @@ class _StoreTodayHero extends StatelessWidget {
                                     : theme.colorScheme.outlineVariant,
                               ),
                             ),
+                          // Textual position next to the dots: the
+                          // ~6-px dots alone were the only position
+                          // cue — unusable for low-vision and
+                          // motor-impaired operators (a11y finding).
+                          // The chevrons stay the big click targets.
+                          Padding(
+                            padding: const EdgeInsets.only(left: 6),
+                            child: Text(
+                              '${currentIndex + 1}/$totalCount',
+                              style: theme.textTheme.labelSmall?.copyWith(
+                                color: theme.colorScheme.onSurfaceVariant,
+                              ),
+                            ),
+                          ),
                         ],
                       ),
                     ),