feat: implement hotspot calculation system with scheduled jobs

- Add hotspot calculation methods to analytics service
- Implement MySQL spatial queries for clustering (5+ reports within 500m)
- Calculate severity scores based on report count and frequency
- Create GET /api/analytics/hotspots endpoint
- Create GET /api/analytics/hotspots/:id endpoint for details
- Create POST /api/analytics/hotspots/calculate for manual trigger
- Implement scheduled job with node-cron (runs every 5 minutes)
- Add comprehensive test scripts for hotspot functionality
- Create detailed implementation documentation

Requirements addressed:
- 3.2: Identify areas with 5+ reports within 500m radius
- 3.3: Rank hotspots by severity score
- 3.4: Update calculations within 5 minutes
- 3.5: Provide data for map visualization with severity indicators

server/src/routes/analyticsRoutes.ts

@@ -10,4 +10,9 @@ router.get('/comparison', analyticsController.getComparison.bind(analyticsContro
 router.get('/export', analyticsController.exportCSV.bind(analyticsController));
 router.get('/aggregated', analyticsController.getAggregatedData.bind(analyticsController));
 
+// Hotspot endpoints
+router.get('/hotspots', analyticsController.getHotspots.bind(analyticsController));
+router.get('/hotspots/:id', analyticsController.getHotspotDetails.bind(analyticsController));
+router.post('/hotspots/calculate', analyticsController.calculateHotspots.bind(analyticsController));
+
 export default router;