fix: export isCommCallPlaying from useCallAudio composable

Same issue as isCommCallPlayable — used in template but not exported/destructured.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/app/components/workspace/CrmWorkspaceApp.vue

@@ -278,6 +278,7 @@ const {
   callTranscriptText,
   callTranscriptError,
   isCommCallPlayable,
+  isCommCallPlaying,
   ensureCommCallWave,
   destroyCommCallWave,
   destroyAllCommCallWaves,

frontend/app/composables/useCallAudio.ts

@@ -433,6 +433,7 @@ export function useCallAudio() {
     stopEventArchiveRecording,
     toggleEventArchiveRecording,
     isCommCallPlayable,
+    isCommCallPlaying,
     setCommCallWaveHost,
   };
 }