Restore accidentally removed files, a few additional import/calculation fixes

inventory-server/dashboard/klaviyo-server/routes/reporting.routes.js

@@ -0,0 +1,29 @@
+import express from 'express';
+import { ReportingService } from '../services/reporting.service.js';
+import { TimeManager } from '../utils/time.utils.js';
+
+export function createReportingRouter(apiKey, apiRevision) {
+  const router = express.Router();
+  const reportingService = new ReportingService(apiKey, apiRevision);
+  const timeManager = new TimeManager();
+
+  // Get campaign reports by time range
+  router.get('/campaigns/:timeRange', async (req, res) => {
+    try {
+      const { timeRange } = req.params;
+      const { channel } = req.query;
+      
+      const reports = await reportingService.getCampaignReports({
+        timeRange,
+        channel
+      });
+
+      res.json(reports);
+    } catch (error) {
+      console.error('[ReportingRoutes] Error fetching campaign reports:', error);
+      res.status(500).json({ error: error.message });
+    }
+  });
+
+  return router;
+}