feat: tooltips universels sur l'ensemble du site

- CampaignsView: Score menace, JA4, ASN, Tendance, Score, Détections, Confiance
- FingerprintsView: colonnes avec tooltips via DataTable
- JA4InvestigationView: IPs Uniques, JA4, ASN, Score
- SubnetInvestigation: colonnes clés avec tooltips
- CorrelationGraph: légende et badges
- EntityInvestigationView: sections headers, JA4, ASN
- IncidentsView: stat cards, sévérité, ASN, Score de risque
- Fix: suppression des imports dupliqués dans CampaignsView

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/components/HeaderFingerprintView.tsx

@@ -241,12 +241,14 @@ export function HeaderFingerprintView() {
     {
       key: 'sec_fetch_mode',
       label: 'Sec-Fetch Mode',
+      tooltip: TIPS.sec_fetch_dest,
       sortable: true,
       render: (v) => <span className="text-text-secondary">{v || '—'}</span>,
     },
     {
       key: 'sec_fetch_dest',
       label: 'Sec-Fetch Dest',
+      tooltip: TIPS.sec_fetch_dest,
       sortable: true,
       render: (v) => <span className="text-text-secondary">{v || '—'}</span>,
     },