feat(desktop): sync knowledge, recordings and shared settings; play any recording

Knowledge documents travel as source-text chunks; each surface embeds them
with its own model, the server index is requested through embed-chunks, and
documents from the phone are stored without a file and indexed from their
chunks. Chunk text is now kept when local embedding fails, so reindexing no
longer needs the original file.

Recordings upload to the mobile storage contract (audio bucket under the
user's folder plus an audio_files row, 50 MiB cap, a Settings > Cloud
toggle) and are removed with their record. The history card gains a play
button that uses the local file or, for phone recordings, a signed URL.

Language (ko/en), system/light/dark theme, auto-polish and the active user
command follow the phone's user_settings with its revision rule; changes that
arrive from the phone reach the open window.

apps/desktop/src/renderer/components/shared/HistoryEntryCard.tsx

@@ -1,9 +1,9 @@
 // src/renderer/components/shared/HistoryEntryCard.tsx
 // High-End Agency Dictation History Card with Audio Telemetry & Instant Actions
 
-import React, { useState, useEffect, useCallback } from 'react'
+import React, { useState, useEffect, useCallback, useRef } from 'react'
 import { Box, IconButton, Tooltip, Chip, Collapse } from '@mui/material'
-import { Copy, Check, Trash2, Tag, X, ScrollText, ChevronDown, Sparkles, Volume2, Star } from 'lucide-react'
+import { Copy, Check, Trash2, Tag, X, ScrollText, ChevronDown, Sparkles, Volume2, Star, Play, Square } from 'lucide-react'
 import { MetalCard, Led, TactileBadge } from '@d3ro/ui/components/ds'
 import { d3roPalette, d3roFontSans, d3roFontMono, d3roTypo, d3roRadius, d3roShadow } from '@d3ro/ui/theme'
 import { useI18n } from '@d3ro/i18n'
@@ -40,6 +40,56 @@ export function HistoryEntryCard({
   const [summaryLoading, setSummaryLoading] = useState(false)
   const [copied, setCopied] = useState(false)
   const hasSummary = !!entry.summaryText
+  const [audioState, setAudioState] = useState<'idle' | 'loading' | 'playing' | 'unavailable'>('idle')
+  const audioRef = useRef<HTMLAudioElement | null>(null)
+  const objectUrlRef = useRef<string | null>(null)
+
+  const stopAudio = useCallback((next: 'idle' | 'unavailable' = 'idle') => {
+    audioRef.current?.pause()
+    audioRef.current = null
+    if (objectUrlRef.current) {
+      URL.revokeObjectURL(objectUrlRef.current)
+      objectUrlRef.current = null
+    }
+    setAudioState(next)
+  }, [])
+
+  useEffect(() => () => stopAudio(), [stopAudio])
+
+  // 이 기기 녹음은 파일 바이트로, 모바일·웹 녹음은 서명 URL로 재생한다.
+  const handleToggleAudio = useCallback(
+    async (e: React.MouseEvent) => {
+      e.stopPropagation()
+      if (audioState === 'playing') {
+        stopAudio()
+        return
+      }
+      setAudioState('loading')
+      try {
+        const result = await window.electronAPI.history.getAudio({ id: entry.id })
+        if (!result.success || !result.data) {
+          stopAudio('unavailable')
+          return
+        }
+        let src: string
+        if (result.data.kind === 'local') {
+          src = URL.createObjectURL(new Blob([result.data.bytes.slice()], { type: result.data.mimeType }))
+          objectUrlRef.current = src
+        } else {
+          src = result.data.url
+        }
+        const audio = new Audio(src)
+        audioRef.current = audio
+        audio.onended = () => stopAudio()
+        audio.onerror = () => stopAudio('unavailable')
+        await audio.play()
+        setAudioState('playing')
+      } catch {
+        stopAudio('unavailable')
+      }
+    },
+    [audioState, entry.id, stopAudio],
+  )
 
   const loadTags = useCallback(async () => {
     if (!showTags) return
@@ -163,6 +213,39 @@ export function HistoryEntryCard({
 
             {/* Quick Action Buttons */}
             <Box sx={{ display: 'flex', alignItems: 'center', gap: 0.5, flexShrink: 0 }}>
+              {entry.duration > 0 && (
+                <Tooltip
+                  title={
+                    audioState === 'playing'
+                      ? t('history.stopAudio')
+                      : audioState === 'unavailable'
+                        ? t('history.audioUnavailable')
+                        : t('history.playAudio')
+                  }
+                >
+                  <span>
+                    <IconButton
+                      size="small"
+                      aria-label={audioState === 'playing' ? t('history.stopAudio') : t('history.playAudio')}
+                      disabled={audioState === 'loading'}
+                      onClick={(e) => void handleToggleAudio(e)}
+                      sx={{
+                        p: 0.6,
+                        color:
+                          audioState === 'playing'
+                            ? d3roPalette.accent.main
+                            : audioState === 'unavailable'
+                              ? d3roPalette.tag.red
+                              : d3roPalette.text.inactive,
+                        bgcolor: audioState === 'playing' ? d3roPalette.accent.dim : 'transparent',
+                        '&:hover': { color: d3roPalette.text.primary, bgcolor: d3roPalette.glass.raised },
+                      }}
+                    >
+                      {audioState === 'playing' ? <Square size={13} /> : <Play size={14} />}
+                    </IconButton>
+                  </span>
+                </Tooltip>
+              )}
               {onToggleFavorite && (
                 <Tooltip title={entry.isFavorite ? t('history.unfavorite') : t('history.favorite')}>
                   <IconButton