feat(ui): Midnight Glass v2 마감 — lucide 아이콘 통일 + 몰입 패널 웨이브 + 팝업 정합

- @mui/icons-material → lucide-react 전환 (23파일, 잔여 0)
- VoiceRecordingPanel: 9바 DOM 웨이브 → GradientWave (canvas)
- Vanilla 팝업 5종 style.css v2 정합 (글래스 네이비/헤어라인/블루,
  CSS 변수 주입 구조 유지 — 테마 반응형 보존)

apps/desktop/src/renderer/components/OnboardingModal.tsx

@@ -21,9 +21,7 @@ import {
   Box,
   LinearProgress,
 } from '@mui/material'
-import CheckCircleOutlineIcon from '@mui/icons-material/CheckCircleOutline'
-import ErrorOutlineIcon from '@mui/icons-material/ErrorOutline'
-import CloudDownloadIcon from '@mui/icons-material/CloudDownload'
+import { CheckCircle2, AlertCircle, CloudDownload } from 'lucide-react'
 import { d3roPalette, d3roRadius, typoSx } from '@d3ro/ui/theme'
 import { useI18n } from '@d3ro/i18n'
 
@@ -281,11 +279,11 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
         }}
       >
         {isSuccess ? (
-          <CheckCircleOutlineIcon sx={{ color: colorSuccess }} />
+          <CheckCircle2 size={24} style={{ color: colorSuccess }} />
         ) : isFailed ? (
-          <ErrorOutlineIcon sx={{ color: colorDanger }} />
+          <AlertCircle size={24} style={{ color: colorDanger }} />
         ) : (
-          <CloudDownloadIcon sx={{ color: colorAccent }} />
+          <CloudDownload size={24} style={{ color: colorAccent }} />
         )}
         {t('onboarding.title')}
       </DialogTitle>