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.

apps/desktop/src/renderer/pages/DictionaryPage.tsx

@@ -36,6 +36,10 @@ export function DictionaryPage(): React.ReactElement {
 
   useEffect(() => {
     loadData()
+    // 다른 기기(모바일·웹)에서 바뀐 사전이 반영되면 다시 불러온다.
+    return window.electronAPI.app.onDataChanged((data) => {
+      if (data.type === 'cloud-sync' && data.entities?.includes('dictionary')) loadData()
+    })
   }, [loadData])
 
   const openAdd = () => {

apps/desktop/src/renderer/pages/HistoryPage.tsx

@@ -86,6 +86,19 @@ export function HistoryPage(): React.ReactElement {
     [loadData],
   )
 
+  const handleToggleFavorite = useCallback(async (entry: HistoryEntry) => {
+    const next = !entry.isFavorite
+    const apply = (value: boolean): void =>
+      setData((prev) =>
+        prev
+          ? { ...prev, entries: prev.entries.map((e) => (e.id === entry.id ? { ...e, isFavorite: value } : e)) }
+          : prev,
+      )
+    apply(next)
+    const result = await window.electronAPI.history.setFavorite({ id: entry.id, isFavorite: next })
+    if (!result.success) apply(entry.isFavorite)
+  }, [])
+
   const handleTagClick = useCallback((tag: string) => {
     setActiveTag((prev) => (prev === tag ? null : tag))
     setSearch('')
@@ -232,6 +245,7 @@ export function HistoryPage(): React.ReactElement {
                   entry={entry}
                   onCopy={handleCopy}
                   onDelete={handleDelete}
+                  onToggleFavorite={handleToggleFavorite}
                   showTags
                   onTagClick={handleTagClick}
                 />

apps/desktop/src/renderer/pages/MeetingModePage.tsx

@@ -197,6 +197,25 @@ export function MeetingModePage(): React.ReactElement {
     if (view === 'list') loadSessions()
   }, [view, loadSessions])
 
+  // 다른 기기(모바일·웹)의 회의 변경이 반영되면: 목록은 다시 불러오고,
+  // 보고 있던 회의가 지워졌으면 목록으로 돌아간다(편집 중인 상세는 덮어쓰지 않는다).
+  useEffect(
+    () =>
+      window.electronAPI.app.onDataChanged((data) => {
+        if (data.type !== 'cloud-sync') return
+        const entities = data.entities ?? []
+        if (!entities.some((e) => e === 'meetings' || e === 'meeting_memos' || e === 'meeting_documents')) return
+        if (view === 'list') {
+          loadSessions()
+        } else if (view === 'detail' && detail) {
+          window.electronAPI.meetingMode.getSession({ sessionId: detail.id }).then((resp) => {
+            if (!resp.success) setView('list')
+          })
+        }
+      }),
+    [view, detail, loadSessions],
+  )
+
   // ── IPC 이벤트 구독 ──
   useEffect(() => {
     const unsubState = window.electronAPI.meetingMode.onStateChanged((info) => {