fix(desktop): surface configuration and provider failures instead of hiding them

Several desktop paths quietly substituted defaults or partial results: a
config write could fall back to a throwaway in-memory store, speech provider
errors were absorbed into empty transcriptions, and meeting exports built
file names from raw titles.

Writes now fail explicitly when the store is unavailable, provider and model
failures reach the UI as errors, and export names pass through one
sanitizer. Settings, license, ad, and support surfaces use the shared theme
tokens, unused hotkey helpers are gone, and the package gains strict
node/renderer typecheck configs plus red-team e2e scenarios for these flows.

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

@@ -59,7 +59,6 @@ class MeetingModeService extends EventEmitter {
 
   /** Phase 15.5-2: 녹음 중 오디오 WAV 파일 보존 */
   private _audioBuffersForFile: Buffer[] = []
-  private _audioFilePath: string | null = null
 
   // Phase 15: Meeting AI Chat
   private _chatHistory: Array<{ role: 'user' | 'assistant'; content: string }> = []
@@ -369,7 +368,6 @@ class MeetingModeService extends EventEmitter {
           if (!fs.existsSync(audioDir)) fs.mkdirSync(audioDir, { recursive: true })
           const wavPath = path.join(audioDir, `${sessionId}.wav`)
           this._saveWav(wavPath, Buffer.concat(this._audioBuffersForFile))
-          this._audioFilePath = wavPath
           logger.info(`회의 오디오 저장: ${wavPath}`)
         } catch (err) {
           logger.warn(`오디오 저장 실패: ${err instanceof Error ? err.message : String(err)}`)
@@ -560,7 +558,6 @@ class MeetingModeService extends EventEmitter {
     this._memos = []
     this._meetingModeActive = false
     this._audioBuffersForFile = []
-    this._audioFilePath = null
   }
 
   /** PCM16 버퍼를 WAV 파일로 저장 (16kHz mono 16-bit) */
@@ -745,7 +742,7 @@ class MeetingModeService extends EventEmitter {
       title: docTitle,
       content: result.text,
       promptUsed: systemPrompt,
-      llmModel: result.model,
+      llmModel: result.model ?? null,
       llmLatencyMs,
       createdAt: now,
       updatedAt: now,
@@ -797,7 +794,7 @@ class MeetingModeService extends EventEmitter {
 
   // ── Phase 14.5: 문서 내보내기 ──
 
-  async exportDocument(documentId: string, format: MeetingExportFormat): Promise<string> {
+  async exportDocument(documentId: string, format: MeetingExportFormat, targetPath?: string): Promise<string> {
     const db = getDatabase()
     const row = db.select().from(meetingDocuments).where(eq(meetingDocuments.id, documentId)).get()
     if (!row) {
@@ -829,25 +826,27 @@ class MeetingModeService extends EventEmitter {
         break
     }
 
-    if (isShowingMeetingSaveDialog) {
-      return ''
-    }
-    isShowingMeetingSaveDialog = true
-    let filePath: string | undefined
-    try {
-      const { getMainWindow } = await import('../windows/WindowManager')
-      const mainWindow = getMainWindow()
-      const dialogOptions = {
-        title: '문서 내보내기',
-        defaultPath: defaultName,
-        filters,
+    let filePath: string | undefined = targetPath
+    if (!filePath) {
+      if (isShowingMeetingSaveDialog) {
+        return ''
+      }
+      isShowingMeetingSaveDialog = true
+      try {
+        const { getMainWindow } = await import('../windows/WindowManager')
+        const mainWindow = getMainWindow()
+        const dialogOptions = {
+          title: '문서 내보내기',
+          defaultPath: defaultName,
+          filters,
+        }
+        const res = mainWindow
+          ? await dialog.showSaveDialog(mainWindow, dialogOptions)
+          : await dialog.showSaveDialog(dialogOptions)
+        filePath = res.filePath
+      } finally {
+        isShowingMeetingSaveDialog = false
       }
-      const res = mainWindow
-        ? await dialog.showSaveDialog(mainWindow, dialogOptions)
-        : await dialog.showSaveDialog(dialogOptions)
-      filePath = res.filePath
-    } finally {
-      isShowingMeetingSaveDialog = false
     }
     if (!filePath) return ''
 
@@ -900,7 +899,7 @@ class MeetingModeService extends EventEmitter {
     return filePath
   }
 
-  async exportTranscript(sessionId: string): Promise<string> {
+  async exportTranscript(sessionId: string, targetPath?: string): Promise<string> {
     const db = getDatabase()
     const row = db.select().from(meetingSessions).where(eq(meetingSessions.id, sessionId)).get()
     if (!row) {
@@ -911,11 +910,15 @@ class MeetingModeService extends EventEmitter {
     const dateStr = formatDateFile(row.startedAt)
     const safeTitle = (row.title ?? '무제_회의').replace(/[/\\?%*:|"<>]/g, '-').slice(0, 50)
 
-    const { filePath } = await dialog.showSaveDialog({
-      title: '전사 내보내기',
-      defaultPath: `전사_${safeTitle}_${dateStr}.txt`,
-      filters: [{ name: 'Text', extensions: ['txt'] }],
-    })
+    let filePath: string | undefined = targetPath
+    if (!filePath) {
+      const res = await dialog.showSaveDialog({
+        title: '전사 내보내기',
+        defaultPath: `전사_${safeTitle}_${dateStr}.txt`,
+        filters: [{ name: 'Text', extensions: ['txt'] }],
+      })
+      filePath = res.filePath
+    }
     if (!filePath) return ''
 
     fs.writeFileSync(filePath, transcript, 'utf-8')