⬆️(frontend) replace NodeJS.Timeout with ReturnType<typeof setTimeout>

Removes Node.js type dependency from browser/React code by substituting
the non-portable `NodeJS.Timeout` type with the standard
`ReturnType<typeof setTimeout>` equivalent across all affected files.

Also replaces `process.env.NODE_ENV` in Icon.tsx with
`import.meta.env.MODE` for Vite compatibility.

src/frontend/package-lock.json

@@ -44,7 +44,6 @@
         "@tanstack/eslint-plugin-query": "5.100.14",
         "@tanstack/react-query-devtools": "5.100.14",
         "@types/humanize-duration": "3.27.4",
-        "@types/node": "24.12.4",
         "@types/react": "18.3.12",
         "@types/react-dom": "18.3.1",
         "@vitejs/plugin-react": "6.0.2",
@@ -58,7 +57,7 @@
         "postcss": "8.5.15",
         "prettier": "3.8.3",
         "rollup-plugin-visualizer": "7.0.1",
-        "typescript": "5.8.3",
+        "typescript": "6.0.3",
         "typescript-eslint": "8.60.1",
         "vite": "8.0.14",
         "vite-plugin-svgr": "5.2.0",
@@ -12611,9 +12610,9 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.8.3",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.8.3.tgz",
-      "integrity": "sha512-p1diW6TqL9L07nNxvRMM7hMMw4c5XOo/1ibL4aAIGmSAt9slTE1Xgw5KWuof2uTOvCg9BY7ZRi+GaF+7sfgPeQ==",
+      "version": "6.0.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-6.0.3.tgz",
+      "integrity": "sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw==",
       "devOptional": true,
       "license": "Apache-2.0",
       "bin": {

src/frontend/package.json

@@ -51,7 +51,6 @@
     "@tanstack/eslint-plugin-query": "5.100.14",
     "@tanstack/react-query-devtools": "5.100.14",
     "@types/humanize-duration": "3.27.4",
-    "@types/node": "24.12.4",
     "@types/react": "18.3.12",
     "@types/react-dom": "18.3.1",
     "@vitejs/plugin-react": "6.0.2",
@@ -65,7 +64,7 @@
     "postcss": "8.5.15",
     "prettier": "3.8.3",
     "rollup-plugin-visualizer": "7.0.1",
-    "typescript": "5.8.3",
+    "typescript": "6.0.3",
     "typescript-eslint": "8.60.1",
     "vite": "8.0.14",
     "vite-plugin-svgr": "5.2.0",

src/frontend/src/features/notifications/components/WaitingParticipantNotification.tsx

@@ -22,7 +22,7 @@ export const WaitingParticipantNotification = () => {
     keyPrefix: 'waitingParticipants',
   })
 
-  const timerRef = useRef<NodeJS.Timeout | null>(null)
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
   const { isParticipantsOpen, toggleParticipants } = useSidePanel()
   const [showQuickActionsMessage, setShowQuickActionsMessage] = useState(false)
   const { waitingParticipants, handleParticipantEntry } =

src/frontend/src/features/recording/components/ControlsButton.tsx

@@ -57,7 +57,7 @@ export const ControlsButton = ({
   const isRoomConnected = room.state == ConnectionState.Connected
 
   const [showSaving, setShowSaving] = useState(false)
-  const timeoutRef = useRef<NodeJS.Timeout>()
+  const timeoutRef = useRef<ReturnType<typeof setTimeout>>()
 
   const isSaving = statuses.isSaving || isPendingToStop
   const isDisabled = !isRoomConnected || statuses.isAnotherModeStarted

src/frontend/src/features/recording/components/RequestRecording.tsx

@@ -19,7 +19,7 @@ export const RequestRecording = ({
   handleRequest,
 }: RequestRecordingProps) => {
   const [isDisabled, setIsDisabled] = useState(false)
-  const timeoutRef = useRef<NodeJS.Timeout>()
+  const timeoutRef = useRef<ReturnType<typeof setTimeout>>()
 
   useEffect(() => {
     return () => {

src/frontend/src/features/rooms/hooks/useLobby.ts

@@ -20,7 +20,7 @@ export const useLobby = ({
   onAccepted: (e: ApiRequestEntry) => void
 }) => {
   const [status, setStatus] = useState(ApiLobbyStatus.IDLE)
-  const waitingTimeoutRef = useRef<NodeJS.Timeout | null>(null)
+  const waitingTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null)
 
   const clearWaitingTimeout = useCallback(() => {
     if (waitingTimeoutRef.current) {

src/frontend/src/features/rooms/hooks/useWatchPermissions.ts

@@ -7,7 +7,7 @@ const POLLING_TIME = 500
 export const useWatchPermissions = () => {
   useEffect(() => {
     let cleanup: (() => void) | undefined
-    let intervalId: NodeJS.Timeout | undefined
+    let intervalId: ReturnType<typeof setTimeout> | undefined
     let isCancelled = false
 
     const checkPermissions = async () => {

src/frontend/src/features/rooms/livekit/components/controls/HandToggle.tsx

@@ -22,7 +22,7 @@ export const HandToggle = () => {
   })
 
   const isSpeaking = room.localParticipant.isSpeaking
-  const speakingTimerRef = useRef<NodeJS.Timeout | null>(null)
+  const speakingTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
   const [hasShownToast, setHasShownToast] = useState(false)
 
   const resetToastState = () => {

src/frontend/src/hooks/useRateLimiter.ts

@@ -14,7 +14,9 @@ export default function useRateLimiter<T extends (...args: any[]) => any>({
   windowMs = 1000,
 }: RateLimiterProps<T>) {
   const callsCountRef = useRef(0)
-  const resetTimeoutRef = useRef<NodeJS.Timeout | undefined>(undefined)
+  const resetTimeoutRef = useRef<ReturnType<typeof setTimeout> | undefined>(
+    undefined
+  )
 
   const rateLimitedFn = useCallback(
     (...args: Parameters<T>) => {

src/frontend/src/hooks/useSyncAfterDelay.ts

@@ -8,7 +8,7 @@ import { useEffect, useRef, useState } from 'react'
  */
 export function useSyncAfterDelay<T>(value: T, waitFor: number = 300) {
   const valueRef = useRef(value)
-  const timeoutRef = useRef<NodeJS.Timeout>()
+  const timeoutRef = useRef<ReturnType<typeof setTimeout>>()
   const [syncValue, setSyncValue] = useState<T>()
 
   useEffect(() => {

src/frontend/src/primitives/Icon.tsx

@@ -56,7 +56,7 @@ export const Icon = ({ name, ...props }: IconProps) => {
   const SvgIcon = icons[name]
 
   if (!SvgIcon) {
-    if (process.env.NODE_ENV !== 'production') {
+    if (import.meta.env.NODE_ENV !== 'production') {
       console.warn(
         `[Icon] Unknown icon name: "${name}". Available: ${Object.keys(icons).join(', ')}`
       )