feat(triage): Ivanti findings trend chart + rename Reporting to Vulnerability Triage

Add time-based open/closed tracking for Ivanti findings (Tier 2 from
the reporting recommendations doc) and rename the Reporting page to
Vulnerability Triage to better reflect its purpose.

Backend — ivantiFindings.js:
  - Create ivanti_counts_history table (appended on every sync, never
    overwritten — Option B from design discussion)
  - INSERT snapshot after each successful syncClosedCount() call
  - GET /api/ivanti/findings/counts/history endpoint — returns last
    snapshot per calendar day using ROW_NUMBER window function, so
    multiple daily syncs collapse to the end-of-day value

Frontend:
  - New IvantiCountsChart component: collapsible dual-line chart
    (open vs closed) with dark tooltip, delta label showing change
    since previous day, and graceful no-data states
  - Chart placed between the donut metrics panel and the findings table
    on the Vulnerability Triage page
  - Renamed page: 'reporting' → 'triage' (page ID, nav label, component
    export, all cross-file references)
  - ComplianceDetailPanel "View in Reporting" link updated to "View in
    Triage" and navigates to the correct page ID

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

frontend/src/components/pages/ComplianceDetailPanel.js

@@ -333,7 +333,7 @@ function MetricRow({ metric, resolved, onNavigate }) {
                     </div>
                     {onNavigate && (
                         <button
-                            onClick={e => { e.stopPropagation(); onNavigate('reporting'); }}
+                            onClick={e => { e.stopPropagation(); onNavigate('triage'); }}
                             style={{
                                 flexShrink: 0, marginLeft: '0.5rem',
                                 background: 'rgba(14,165,233,0.1)',
@@ -348,7 +348,7 @@ function MetricRow({ metric, resolved, onNavigate }) {
                             onMouseEnter={e => { e.currentTarget.style.background = 'rgba(14,165,233,0.18)'; e.currentTarget.style.borderColor = 'rgba(14,165,233,0.7)'; }}
                             onMouseLeave={e => { e.currentTarget.style.background = 'rgba(14,165,233,0.1)'; e.currentTarget.style.borderColor = 'rgba(14,165,233,0.4)'; }}
                         >
-                            View in Reporting →
+                            View in Triage →
                         </button>
                     )}
                 </div>