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/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}
                 />