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

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

@@ -0,0 +1,17 @@
+import express from 'express';
+import { createEventsRouter } from './events.routes.js';
+import { createMetricsRoutes } from './metrics.routes.js';
+import { createCampaignsRouter } from './campaigns.routes.js';
+import { createReportingRouter } from './reporting.routes.js';
+
+export function createApiRouter(apiKey, apiRevision) {
+  const router = express.Router();
+
+  // Mount routers
+  router.use('/events', createEventsRouter(apiKey, apiRevision));
+  router.use('/metrics', createMetricsRoutes(apiKey, apiRevision));
+  router.use('/campaigns', createCampaignsRouter(apiKey, apiRevision));
+  router.use('/reporting', createReportingRouter(apiKey, apiRevision));
+
+  return router;
+}