feat(prospecting): add security audit report generation (Workstream 2B)

- SecurityReportService generates standalone branded HTML reports from
  stored audit data (grade badge, simulated hacked site, detailed
  findings, business impact, call-to-action with contact info)
- GET /security-audit/report/{prospect_id} returns HTMLResponse
- "Generate Report" button on prospect detail security tab opens
  report in new browser tab (printable to PDF)

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

app/modules/prospecting/static/admin/js/prospect-detail.js

@@ -117,6 +117,10 @@ function prospectDetail(prospectId) {
             }
         },
 
+        openSecurityReport() {
+            window.open('/api/v1/admin/prospecting/enrichment/security-audit/report/' + this.prospectId, '_blank');
+        },
+
         async runSecurityAudit() {
             this.auditRunning = true;
             try {