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/static/css/style.css

@@ -995,3 +995,41 @@ tr.mapping-deleted td {
     margin: 0;
     cursor: pointer;
 }
+
+/* ── Attention card ──────────────────────────── */
+.attention-card {
+    display: flex;
+    align-items: center;
+    gap: 16px;
+    padding: 10px 16px;
+    border-radius: 8px;
+    font-size: 0.875rem;
+    margin-bottom: 8px;
+}
+.attention-ok {
+    background: var(--success-light);
+    color: var(--success-text);
+}
+.attention-alert {
+    background: var(--surface);
+    border: 1px solid var(--border);
+    flex-wrap: wrap;
+}
+.attention-item {
+    display: inline-flex;
+    align-items: center;
+    gap: 4px;
+    padding: 4px 10px;
+    border-radius: 4px;
+    cursor: pointer;
+    transition: opacity 0.15s;
+}
+.attention-item:hover { opacity: 0.8; }
+.attention-error {
+    background: var(--error-light);
+    color: var(--error-text);
+}
+.attention-warning {
+    background: var(--warning-light);
+    color: var(--warning-text);
+}