fix(core): audio block actions not showing (#12527)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

- **Style**
  - Updated audio block containers to remove borders and allow visible overflow, improving the appearance of audio attachments.

- **Bug Fixes**
  - Ensured that the actions field is always present in audio transcription job results, defaulting to an empty string when not specified.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/modules/media/entities/audio-transcription-job.ts

@@ -244,6 +244,7 @@ export class AudioTranscriptionJob extends Entity<{
       const result: TranscriptionResult = {
         summary: claimedJob.summary ?? '',
         title: claimedJob.title ?? '',
+        actions: claimedJob.actions ?? '',
         segments:
           claimedJob.transcription?.map(segment => ({
             speaker: segment.speaker,