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

backend/app/routers/tests.py

@@ -54,6 +54,8 @@ from app.services.test_workflow_service import (
     reopen_test as wf_reopen,
     handle_remediation_completed as wf_handle_remediation,
     get_retest_chain as wf_get_retest_chain,
+    pause_timer as wf_pause_timer,
+    resume_timer as wf_resume_timer,
 )
 
 router = APIRouter(prefix="/tests", tags=["tests"])
@@ -473,6 +475,42 @@ def submit_blue(
     return test
 
 
+# ---------------------------------------------------------------------------
+# POST /tests/{id}/pause-timer  —  pause the active phase timer
+# ---------------------------------------------------------------------------
+
+
+@router.post("/{test_id}/pause-timer", response_model=TestOut)
+def pause_timer(
+    test_id: uuid.UUID,
+    db: Session = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+):
+    """Pause the running timer for the current phase (red_executing or blue_evaluating)."""
+    test = _get_test_or_404(db, test_id)
+    test = wf_pause_timer(db, test, current_user)
+    db.refresh(test)
+    return test
+
+
+# ---------------------------------------------------------------------------
+# POST /tests/{id}/resume-timer  —  resume a paused phase timer
+# ---------------------------------------------------------------------------
+
+
+@router.post("/{test_id}/resume-timer", response_model=TestOut)
+def resume_timer(
+    test_id: uuid.UUID,
+    db: Session = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+):
+    """Resume the paused timer for the current phase."""
+    test = _get_test_or_404(db, test_id)
+    test = wf_resume_timer(db, test, current_user)
+    db.refresh(test)
+    return test
+
+
 # ---------------------------------------------------------------------------
 # POST /tests/{id}/validate-red  —  Red Lead validates
 # ---------------------------------------------------------------------------