feat: V2-7 Admin 콘솔 리디자인 + 3단계 권한 + SaaS 전환 + 코드 정리

- Admin CRM: D3RO Console 스타일 전체 적용 (panelSx/tableSx/filterBtnSx)
- 3단계 권한: manager/admin/super_admin (DB + Edge Functions + Frontend)
- 랜딩 페이지: 1회 결제 → 월간/연간 구독 SaaS 모델 (10개 언어)
- SSE 스트리밍: VoiceConversation Premium LLM 라우팅 + fallback
- Supabase 클라이언트: packages/api-client 공통 추출 (browser+server)
- RPC 함수 타입: 9개 정의 (admin_usage_by_feature 등)
- callAdminApi 401 버그 수정 (getUser() 선행 토큰 갱신)

apps/desktop/src/main/services/VoiceConversationService.ts

@@ -269,18 +269,16 @@ class VoiceConversationService extends EventEmitter {
     this._setState('thinking')
 
     try {
-      // Ollama /api/chat 호출 (스트리밍)
-      const llmService = getLocalLLMService()
-      const chatMessages = this._buildChatMessages()
+      // LLM 백엔드 선택: premium 설정 + 사용 가능 → PremiumLLM, 아니면 LocalLLM
+      const { generator: chatGenerator, backend } = await this._createChatStream()
+      logger.info(`Conversation LLM backend: ${backend}`)
 
       const assistantMsgId = crypto.randomUUID()
       let accumulated = ''
       const ttsSentences: string[] = []
       let sentenceBuffer = ''
 
-      const generator = llmService.chatStream(chatMessages)
-
-      for await (const token of generator) {
+      for await (const token of chatGenerator) {
         accumulated += token
 
         // 렌더러에 델타 전송
@@ -359,6 +357,34 @@ class VoiceConversationService extends EventEmitter {
     }
   }
 
+  /**
+   * LLM 백엔드 선택 + chatStream 생성.
+   * premium 설정 + 사용 가능 → PremiumLLM, 실패 시 LocalLLM fallback.
+   */
+  private async _createChatStream(): Promise<{
+    generator: AsyncGenerator<string, string>
+    backend: 'local' | 'premium'
+  }> {
+    const chatMessages = this._buildChatMessages()
+    const backend = configGet('llmBackend')
+
+    if (backend === 'premium') {
+      try {
+        const { getPremiumLLMService } = await import('./PremiumLLMService')
+        const premium = getPremiumLLMService()
+        if (premium.isAvailable()) {
+          return { generator: premium.chatStream(chatMessages), backend: 'premium' }
+        }
+        logger.warn('Premium LLM not available for conversation, falling back to local')
+      } catch (err) {
+        logger.warn('Premium LLM init failed for conversation:', err instanceof Error ? err.message : String(err))
+      }
+    }
+
+    const local = getLocalLLMService()
+    return { generator: local.chatStream(chatMessages), backend: 'local' }
+  }
+
   private _buildChatMessages(): Array<{ role: string; content: string }> {
     const chatMsgs: Array<{ role: string; content: string }> = [
       { role: 'system', content: SYSTEM_PROMPT },