fix(onboarding): 무진행 구간 UX + 중복 실행 가드

- verifying/manifest 상태(바이트 진행률 없음)에서 인디터미넌트 바 + 친화적 문구
  — 9.6GB 검증 ~2분간 멈춘 것처럼 보이던 문제 해소
- OnboardingModal 중복 실행 가드 (runningRef)
- LocalLLMService.pullModel: 동일 모델 동시 pull은 기존 promise 합류
- LocalSTTService.downloadModel: /download 409는 실패가 아닌 기존 진행 합류

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

@@ -87,7 +87,10 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
   const [status, setStatus] = useState('')
   const [detail, setDetail] = useState('')
   const [errorMsg, setErrorMsg] = useState('')
+  // 진행률 없는 상태(무결성 검증 등) — 인디터미넌트 바로 "멈춘 것처럼" 보이는 문제 방지
+  const [busyStatus, setBusyStatus] = useState(false)
   const activeStepRef = useRef<StepKind | null>(null)
+  const runningRef = useRef(false)
 
   const isVisible = open || internalOpen
 
@@ -127,6 +130,9 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
       if (e.modelId !== DEFAULT_LLM_MODEL) return
       setStatus(e.status)
       if (e.percent > 0) setPercent(e.percent)
+      // total 없는 상태 라인(pulling manifest / verifying / writing manifest)은
+      // 바이트 진행률이 없음 — 인디터미넌트로 표시
+      setBusyStatus(!e.total || e.total === 0)
     })
     return () => {
       unsub()
@@ -153,40 +159,47 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
   }, [t])
 
   const handleDownload = useCallback(async (): Promise<void> => {
+    // 중복 실행 가드 (연타/이중 트리거 방지)
+    if (runningRef.current) return
+    runningRef.current = true
     setPhase('downloading')
     setErrorMsg('')
 
-    // 재시도 시 이미 끝난 단계를 스킵하도록 매번 재계산
-    const needed = await computeNeededSteps()
-    setSttModelId(needed.sttModelId)
-    setNeededSteps(needed.steps)
+    try {
+      // 재시도 시 이미 끝난 단계를 스킵하도록 매번 재계산
+      const needed = await computeNeededSteps()
+      setSttModelId(needed.sttModelId)
+      setNeededSteps(needed.steps)
 
-    for (let i = 0; i < needed.steps.length; i++) {
-      const step = needed.steps[i]
-      setStepIndex(i)
-      setPercent(0)
-      setStatus('')
-      setDetail('')
-      activeStepRef.current = step
+      for (let i = 0; i < needed.steps.length; i++) {
+        const step = needed.steps[i]
+        setStepIndex(i)
+        setPercent(0)
+        setStatus('')
+        setDetail('')
+        setBusyStatus(false)
+        activeStepRef.current = step
 
-      const result =
-        step === 'llm'
-          ? await window.electronAPI.llm.pullModel({ modelId: DEFAULT_LLM_MODEL })
-          : await window.electronAPI.stt.downloadModel({ modelId: needed.sttModelId })
+        const result =
+          step === 'llm'
+            ? await window.electronAPI.llm.pullModel({ modelId: DEFAULT_LLM_MODEL })
+            : await window.electronAPI.stt.downloadModel({ modelId: needed.sttModelId })
 
-      if (!result.success) {
-        activeStepRef.current = null
-        setPhase('failed')
-        setErrorMsg(result.error?.message ?? 'unknown')
-        return
+        if (!result.success) {
+          setPhase('failed')
+          setErrorMsg(result.error?.message ?? 'unknown')
+          return
+        }
+        setPercent(100)
       }
-      setPercent(100)
-    }
 
-    activeStepRef.current = null
-    setPhase('success')
-    // 온보딩 완료 플래그 저장
-    window.electronAPI.config.set({ key: 'onboardingCompleted', value: true })
+      setPhase('success')
+      // 온보딩 완료 플래그 저장
+      window.electronAPI.config.set({ key: 'onboardingCompleted', value: true })
+    } finally {
+      activeStepRef.current = null
+      runningRef.current = false
+    }
   }, [])
 
   const handleClose = useCallback(() => {
@@ -209,6 +222,15 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
     ? (neededSteps[stepIndex] ?? null)
     : null
 
+  // Ollama 원시 status 문자열 → 친화적 문구 (알려진 것만 매핑, 그 외 원문)
+  const formatStatus = (raw: string): string => {
+    if (raw.startsWith('pulling manifest')) return t('onboarding.statusPreparing')
+    if (raw.startsWith('verifying')) return t('onboarding.statusVerifying')
+    if (raw.startsWith('writing manifest') || raw === 'success')
+      return t('onboarding.statusFinalizing')
+    return raw
+  }
+
   /** 단계별 안내 박스 렌더 */
   const renderStepInfo = (step: StepKind): React.ReactElement => (
     <Box
@@ -287,11 +309,11 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
                   : t('onboarding.downloading')}
               </Typography>
               <Typography sx={{ ...typoSx('small'), color: colorAccent }}>
-                {percent}%
+                {busyStatus ? '…' : `${percent}%`}
               </Typography>
             </Box>
             <LinearProgress
-              variant="determinate"
+              variant={busyStatus ? 'indeterminate' : 'determinate'}
               value={percent}
               sx={{ height: 8, borderRadius: d3roRadius.xs }}
             />
@@ -306,7 +328,7 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
               <Typography
                 sx={{ ...typoSx('meta'), color: d3roPalette.text.secondary, mt: 1 }}
               >
-                {t('onboarding.status', { status })}
+                {t('onboarding.status', { status: formatStatus(status) })}
               </Typography>
             )}
           </Box>