feat(safety): needs attention card on dashboard

Add a "Needs Attention" card above the orders table that surfaces:
- Import errors count (click → ERROR filter)
- Unmapped SKUs count (click → Missing SKUs page)
- Uninvoiced orders >3 days (click → UNINVOICED filter)
Shows green "Totul in ordine" when all metrics are zero.

Backend: add uninvoiced_old count to get_orders() and unresolved_skus
from get_dashboard_stats() to dashboard/orders API response.

Cache-bust: style.css?v=21, dashboard.js?v=29

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/templates/dashboard.html

@@ -49,6 +49,7 @@
         <span>Comenzi</span>
     </div>
     <div class="card-body py-2 px-3">
+        <div id="attentionCard"></div>
         <div class="filter-bar" id="ordersFilterBar">
           <!-- Period dropdown -->
           <select id="periodSelect" class="select-compact">
@@ -114,5 +115,5 @@
 {% endblock %}
 
 {% block scripts %}
-<script src="{{ request.scope.get('root_path', '') }}/static/js/dashboard.js?v=28"></script>
+<script src="{{ request.scope.get('root_path', '') }}/static/js/dashboard.js?v=29"></script>
 {% endblock %}