fix(lint): resolve remaining ESLint errors (unused vars, any types, react-refresh)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/firmware/FirmwarePage.tsx

@@ -16,7 +16,6 @@ import {
 } from 'lucide-react'
 import {
   firmwareApi,
-  type FirmwareOverview,
   type DeviceFirmwareStatus,
   type FirmwareVersionGroup,
 } from '@/lib/firmwareApi'
@@ -24,7 +23,6 @@ import { useUIStore } from '@/lib/store'
 import { useAuth, isSuperAdmin, canWrite } from '@/lib/auth'
 import { Button } from '@/components/ui/button'
 import { Checkbox } from '@/components/ui/checkbox'
-import { Label } from '@/components/ui/label'
 import {
   Dialog,
   DialogContent,

frontend/src/components/firmware/UpgradeProgressModal.tsx

@@ -17,10 +17,7 @@ import {
   XCircle,
   PauseCircle,
 } from 'lucide-react'
-import {
-  firmwareApi,
-  type FirmwareUpgradeJob,
-} from '@/lib/firmwareApi'
+import { firmwareApi } from '@/lib/firmwareApi'
 import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/ui/dialog'
 import { Button } from '@/components/ui/button'
 import { cn } from '@/lib/utils'