feat(api): add stats chart endpoint for admin access with time series data

feat(dayjs): integrate dayjs for date handling and formatting across the application
refactor(routes): update date handling in id-tags, transactions, users, and dashboard routes to use dayjs
style(globals): improve CSS variable definitions for better readability and consistency
deps: add dayjs as a dependency for date manipulation

apps/csms/src/ocpp/actions/boot-notification.ts

@@ -1,4 +1,5 @@
 import { useDrizzle } from '@/lib/db.js'
+import dayjs from 'dayjs'
 import { chargePoint } from '@/db/schema.js'
 import type {
   BootNotificationRequest,
@@ -30,7 +31,7 @@ export async function handleBootNotification(
       // New, unknown devices start as Pending — admin must manually accept them
       registrationStatus: 'Pending',
       heartbeatInterval: DEFAULT_HEARTBEAT_INTERVAL,
-      lastBootNotificationAt: new Date(),
+      lastBootNotificationAt: dayjs().toDate(),
     })
     .onConflictDoUpdate({
       target: chargePoint.chargePointIdentifier,
@@ -45,8 +46,8 @@ export async function handleBootNotification(
         meterSerialNumber: payload.meterSerialNumber ?? null,
         // Do NOT override registrationStatus — preserve whatever the admin set
         heartbeatInterval: DEFAULT_HEARTBEAT_INTERVAL,
-        lastBootNotificationAt: new Date(),
-        updatedAt: new Date(),
+        lastBootNotificationAt: dayjs().toDate(),
+        updatedAt: dayjs().toDate(),
       },
     })
     .returning()
@@ -57,7 +58,7 @@ export async function handleBootNotification(
   console.log(`[OCPP] BootNotification ${ctx.chargePointIdentifier} status=${status}`)
 
   return {
-    currentTime: new Date().toISOString(),
+    currentTime: dayjs().toISOString(),
     interval: DEFAULT_HEARTBEAT_INTERVAL,
     status,
   }