refactor(desktop): 라이선스 UI 빅뱅 — 키 입력 제거, 구독 기반 전환

- LicenseTab/LicenseModal: LemonSqueezy 키 입력 삭제, Payple 구독 UI로 전환
- useLicenseState 훅: 라이선스+클라우드 인증 공용 상태 관리 추출
- PREMIUM_MODEL_LIMITS: 3곳 중복 → @d3ro/core/constants 단일 소스
- i18n: LemonSqueezy 전용 키 18개 삭제, 구독 관련 키 13개 추가 (12 locale)
- DashboardPage: dashboard.model* → license.model* 키 통일

apps/desktop/src/renderer/hooks/useLicenseState.ts

@@ -0,0 +1,87 @@
+// src/renderer/hooks/useLicenseState.ts
+// LicenseTab/LicenseModal 공용 — 라이선스 + 클라우드 인증 상태 관리
+
+import { useState, useEffect, useCallback } from 'react'
+import type {
+  LicenseInfo,
+  LicenseTier,
+  UsageQuota,
+  TierComparison,
+} from '@d3ro/core/types'
+
+interface CloudState {
+  authenticated: boolean
+  userEmail: string | null
+}
+
+export interface LicenseState {
+  licenseInfo: LicenseInfo | null
+  usage: UsageQuota[]
+  comparison: TierComparison[]
+  cloud: CloudState
+  currentTier: LicenseTier
+  isFree: boolean
+  isPro: boolean
+  handleUpgrade: (tier: 'pro' | 'pro_plus') => void
+  handleOpenBilling: () => void
+  openCloudSettings: () => void
+}
+
+export function useLicenseState(): LicenseState {
+  const [licenseInfo, setLicenseInfo] = useState<LicenseInfo | null>(null)
+  const [usage, setUsage] = useState<UsageQuota[]>([])
+  const [comparison, setComparison] = useState<TierComparison[]>([])
+  const [cloud, setCloud] = useState<CloudState>({ authenticated: false, userEmail: null })
+
+  const loadData = useCallback(() => {
+    window.electronAPI.license.getInfo().then((r) => {
+      if (r.success) setLicenseInfo(r.data)
+    })
+    window.electronAPI.license.getAllUsage().then((r) => {
+      if (r.success) setUsage(r.data)
+    })
+    window.electronAPI.license.getTierComparison().then((r) => {
+      if (r.success) setComparison(r.data)
+    })
+    window.electronAPI.cloudSync.getState().then((r) => {
+      if (r.success) setCloud({ authenticated: r.data.authenticated, userEmail: r.data.userEmail })
+    })
+  }, [])
+
+  useEffect(() => {
+    loadData()
+    const unsubTier = window.electronAPI.license.onTierChanged(() => loadData())
+    const unsubAuth = window.electronAPI.cloudSync.onAuthChanged((payload) => {
+      setCloud({ authenticated: payload.user !== null, userEmail: payload.user?.email ?? null })
+      loadData()
+    })
+    return () => { unsubTier(); unsubAuth() }
+  }, [loadData])
+
+  const currentTier = licenseInfo?.tier ?? 'free'
+
+  const handleUpgrade = useCallback((tier: 'pro' | 'pro_plus') => {
+    window.electronAPI.license.openBilling({ tier })
+  }, [])
+
+  const handleOpenBilling = useCallback(() => {
+    window.electronAPI.license.openBilling({ tier: 'pro' })
+  }, [])
+
+  const openCloudSettings = useCallback(() => {
+    window.dispatchEvent(new CustomEvent('d3ro:open-settings', { detail: { tab: 'cloud' } }))
+  }, [])
+
+  return {
+    licenseInfo,
+    usage,
+    comparison,
+    cloud,
+    currentTier,
+    isFree: currentTier === 'free',
+    isPro: currentTier === 'pro',
+    handleUpgrade,
+    handleOpenBilling,
+    openCloudSettings,
+  }
+}