feat(phase-37): timer pause/resume + professional reporting engine

Pause/Resume timer:
- Add paused_at, red_paused_seconds, blue_paused_seconds fields to Test model
- Add pause_timer/resume_timer workflow functions with accumulated pause tracking
- Auto-resume on phase submit; subtract paused time from worklog duration
- Add POST /tests/{id}/pause-timer and resume-timer endpoints
- Update LiveTimer component with pause/resume button and paused visual state
- Wire pause/resume mutations through TestDetailPage and TestDetailHeader

Professional Reporting Engine - Fase 2:
- Add ReportEngine service with Jinja2 HTML rendering, WeasyPrint PDF, and docxtpl DOCX
- Add corporate CSS stylesheet with cover page, data tables, stats grid, findings
- Create purple_campaign, coverage_report, and executive_summary HTML templates
- Add report_generation_service collecting domain data for each report type
- Add professional_reports router: GET /reports/generate/purple-campaign/{id}, coverage-summary, executive-summary
- Add analytics router with flat JSON endpoints for PowerBI: /coverage, /tests, /trends, /operators
- Add advanced_metrics router: /coverage-by-tactic, /never-tested, /avg-validation-time, /detection-rate-trend
- Add weasyprint and docxtpl to requirements.txt
- Add REPORT_TEMPLATES_DIR, REPORT_OUTPUT_DIR, COMPANY_NAME, COMPANY_LOGO_PATH to config

frontend/src/pages/TestDetailPage.tsx

@@ -13,6 +13,8 @@ import {
   validateAsRedLead,
   validateAsBlueLead,
   reopenTest,
+  pauseTimer,
+  resumeTimer,
   getTestTimeline,
   getRetestChain,
 } from "../api/tests";
@@ -223,6 +225,25 @@ export default function TestDetailPage() {
     },
   });
 
+  // Timer pause/resume
+  const pauseTimerMutation = useMutation({
+    mutationFn: () => pauseTimer(testId!),
+    onSuccess: () => {
+      invalidateAll();
+      showToast("Timer paused", "success");
+    },
+    onError: (err: unknown) => showToast(extractError(err), "error"),
+  });
+
+  const resumeTimerMutation = useMutation({
+    mutationFn: () => resumeTimer(testId!),
+    onSuccess: () => {
+      invalidateAll();
+      showToast("Timer resumed", "success");
+    },
+    onError: (err: unknown) => showToast(extractError(err), "error"),
+  });
+
   // Evidence upload
   const uploadMutation = useMutation({
     mutationFn: ({ file, team }: { file: File; team: TeamSide }) =>
@@ -351,6 +372,9 @@ export default function TestDetailPage() {
         onSubmitBlue={() => submitBlueMutation.mutate()}
         onOpenValidateModal={(side) => setValidationModal({ open: true, side })}
         onReopen={() => setConfirmReopen(true)}
+        onPauseTimer={() => pauseTimerMutation.mutate()}
+        onResumeTimer={() => resumeTimerMutation.mutate()}
+        isTogglingTimer={pauseTimerMutation.isPending || resumeTimerMutation.isPending}
       />
 
       {/* Content: Tabs + Sidebar */}