feat(desktop): two-way cloud sync with mobile and web

Rewrites the desktop mirror as services/sync/SyncEngine: a persistent
outbox, per-account server-clock keyset cursors with paging, pulls that never
overwrite unsent local edits, deletions both ways through sync_tombstones and
per-row failure isolation. It now covers history titles and favorites,
dictionary, every meeting's memos and documents, memo tags, user commands and
dictation/meeting templates, and registers the desktop as a device that the
phone can disconnect.

Fixes shipped defects: the first pull after sign-in fetched nothing, only
the first meeting's children were pushed, team meetings leaked into the
personal database and lost team_id on re-push, and Realtime never connected
because Electron's Node 20 has no global WebSocket (ws is now the transport).
Anonymous local-mode records are imported into the first account that signs
in. The settings sync section is translated and shows pending/rejected
changes; synced screens reload on app:dataChanged.

packages/core/src/ipc-channels.ts

@@ -145,6 +145,7 @@ export const IPC_CHANNELS = {
     GET_BY_ID: 'history:getById',
     DELETE: 'history:delete',
     DELETE_ALL: 'history:deleteAll',
+    SET_FAVORITE: 'history:setFavorite',
     SEARCH: 'history:search',
     EXPORT: 'history:export',
     // Main → Renderer events

packages/core/src/types.ts

@@ -479,6 +479,12 @@ export interface AppConfig {
   supabaseAnonKey: string
   /** V2-4: 마지막 동기화 epoch ms */
   cloudSyncLastAt: number | null
+  /**
+   * 이 설치본의 기기 식별자(uuid). Supabase devices.installation_id —
+   * 모바일 "연결된 기기" 목록에 이 데스크톱이 나타나고 원격 연결 해제 대상이 된다.
+   * 원격 해제된 id는 재사용할 수 없어(서버 규칙) 재로그인 때 새로 발급한다.
+   */
+  deviceInstallationId: string | null
   /** 빅뱅 Phase 2: 첫 실행 온보딩 완료 여부 (로컬 모드 entry point) */
   onboardingCompleted: boolean
   /** Phase 6: Custom instructions (CustomInstructionService) */
@@ -622,6 +628,8 @@ export interface HistoryEntry {
   appVersion: string
   /** Phase 12.2: 회의록 요약 마크다운 */
   summaryText: string | null
+  /** 모바일·웹과 공유하는 즐겨찾기 (Supabase history.is_favorite) */
+  isFavorite: boolean
 }
 
 export interface HistoryQueryParams {
@@ -647,6 +655,11 @@ export interface HistoryDeleteParams {
   id: string
 }
 
+export interface HistorySetFavoriteParams {
+  id: string
+  isFavorite: boolean
+}
+
 export interface HistorySearchParams {
   query: string
   page: number