feat(desktop): Premium LLM SSE 스트리밍 — 토큰 단위 실시간 응답

- sse-parser.ts: Anthropic SSE 파서 (content_block_delta.text 추출)
- CloudSyncService.invokeFunctionStream(): raw fetch + SSE ReadableStream
- PremiumLLMService.chatStream(): stream=true, 토큰 단위 yield
- SSE 실패 시 자동 비스트리밍 fallback
- AbortController 연결 (취소 지원)

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

@@ -425,6 +425,62 @@ class CloudSyncService extends EventEmitter {
     return { data, error: null }
   }
 
+  /**
+   * Edge Function 스트리밍 호출 — SSE 응답의 ReadableStream 반환.
+   * Supabase JS의 functions.invoke()는 JSON 자동 파싱하므로 SSE에 부적합.
+   * raw fetch + auth 토큰으로 직접 호출.
+   */
+  async invokeFunctionStream(
+    name: string,
+    body: Record<string, unknown>,
+    signal?: AbortSignal,
+  ): Promise<{ stream: ReadableStream<Uint8Array> | null; error: { message: string } | null }> {
+    if (!this._client) {
+      return { stream: null, error: { message: 'Supabase client not initialized' } }
+    }
+
+    const { data: sessionData } = await this._client.auth.getSession()
+    const token = sessionData.session?.access_token
+    if (!token) {
+      return { stream: null, error: { message: 'No active session — 로그인 필요' } }
+    }
+
+    const url = configGet('supabaseUrl') as string | undefined
+    const anonKey = configGet('supabaseAnonKey') as string | undefined
+    if (!url || !anonKey) {
+      return { stream: null, error: { message: 'Supabase URL/key not configured' } }
+    }
+
+    try {
+      const response = await fetch(`${url}/functions/v1/${name}`, {
+        method: 'POST',
+        headers: {
+          Authorization: `Bearer ${token}`,
+          apikey: anonKey,
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify(body),
+        signal,
+      })
+
+      if (!response.ok) {
+        const text = await response.text()
+        return { stream: null, error: { message: `${response.status}: ${text}` } }
+      }
+
+      if (!response.body) {
+        return { stream: null, error: { message: 'No response body' } }
+      }
+
+      return { stream: response.body, error: null }
+    } catch (err) {
+      if ((err as Error).name === 'AbortError') {
+        return { stream: null, error: { message: 'Request aborted' } }
+      }
+      return { stream: null, error: { message: err instanceof Error ? err.message : String(err) } }
+    }
+  }
+
   getState(): CloudSyncState {
     return {
       authenticated: this.isAuthenticated(),