refactor(main): ipcSuccess/ipcError 헬퍼 통일 + catch(error) 패턴 (WS-PATTERN)

- cloud-sync-handlers 수동 ok/fail -> ipcSuccess/ipcError 헬퍼 (6 핸들러)
- catch {} -> catch(error) 에러 메시지 보강 32건 (11 ipc handler 파일)
KEEP: template-handlers(주석 명시 에러 무시), license-handlers(이미 헬퍼 사용),
       audio-handlers stop().catch(() => {})(의도적 무시)
정책: docs/REFACTOR_POLICY.md DP2

apps/desktop/src/main/ipc/memo-handlers.ts

@@ -17,8 +17,9 @@ export function registerMemoHandlers(): void {
   ipcMain.handle(IPC_CHANNELS.MEMO.GET_TAGS, async (_event, params: GetTagsParams) => {
     try {
       return ipcSuccess(getMemoService().getTagsForEntry(params.historyId))
-    } catch {
-      return ipcError(ErrorCode.DBQueryFailed, 'Failed to get tags for history entry')
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error)
+      return ipcError(ErrorCode.DBQueryFailed, `Failed to get tags for history entry: ${message}`)
     }
   })
 
@@ -48,16 +49,18 @@ export function registerMemoHandlers(): void {
   ipcMain.handle(IPC_CHANNELS.MEMO.GET_ALL_TAGS, async () => {
     try {
       return ipcSuccess(getMemoService().getAllTags())
-    } catch {
-      return ipcError(ErrorCode.DBQueryFailed, 'Failed to get all tags')
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error)
+      return ipcError(ErrorCode.DBQueryFailed, `Failed to get all tags: ${message}`)
     }
   })
 
   ipcMain.handle(IPC_CHANNELS.MEMO.SEARCH_BY_TAG, async (_event, params: SearchByTagParams) => {
     try {
       return ipcSuccess(getMemoService().searchByTag(params))
-    } catch {
-      return ipcError(ErrorCode.DBQueryFailed, 'Failed to search by tag')
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error)
+      return ipcError(ErrorCode.DBQueryFailed, `Failed to search by tag: ${message}`)
     }
   })