Improve In-App Media Player for audio files to Look and behave Like Telegram

### Feature request
**Which Nextcloud Version are you currently using:**
Nextcloud Hub 9 (Talk iOS App)
**Is your feature request related to a problem? Please describe.**
I'm always frustrated when standard audio files (like .mp3, .m4a, or .wav) sent in a chat are displayed as clunky generic file attachments. This takes up a lot of space in the chat history and lacks a proper, compact in-app media player integration for regular audio files on iOS.
**Describe the solution you'd like**
I would like regular audio files to be displayed in a compact chat bubble similar to voice messages. It should feature a clean, round Play/Pause button, display the actual filename or ID3 metadata (Title/Artist), and show a simple, linear progression bar instead of the voice message waveform if no amplitude data is present.
Furthermore, it should behave exactly like Telegram's audio player:
* It needs to support background playback so music/audio keeps playing when the app is closed, showing a persistent media control interface in the iOS Control Center and Lock Screen (Now Playing integration).
* It should automatically queue and skip to the next available audio file in the chat history once the current track finishes.
Many users are currently looking for secure, self-hosted alternatives to Telegram, and having a polished, fully-featured media player on iOS is a key feature to convincing them to switch to Nextcloud Talk.
**Describe alternatives you've considered**
Leaving it as a generic file download, which forces users to use external iOS media players or clutters the chat view.
**Additional context**
This would drastically improve the user experience when sharing music, podcasts, or longer audio recordings within Talk on iOS, bringing the chat UI closer to modern messengers like Telegram or Signal.

The issue names no files, tests, or entry points. Start by locating the Talk iOS audio-attachment and playback implementation, then verify compact rendering, filename or metadata display, linear progress, background Now Playing controls, and queue advancement. Done means regular audio files behave as described without remaining generic attachments.

Written by the indexing model from the issue text.