Local file playback (Winamp mode)

[rmzi]

Summary

Add the ability to play local audio files through the player UI — no server needed, works entirely offline.

Motivation

The player already has solid audio controls, queue management, and PWA offline support. Local file playback would make it useful as a general-purpose music player even without a deployed catalog.

Proposed approach

• File picker (<input type="file" accept="audio/*" multiple>) + drag & drop (desktop)
• Read ID3 tags client-side (e.g. music-metadata-browser), fall back to filename
• Local tracks feed into the same <audio> element and player controls
• Streaming catalog and local files coexist in the queue

Platform notes

• Desktop: Full support (file picker + drag & drop)
• iOS PWA: File picker only (no File System Access API, no drag & drop)
• Android PWA: Full support

Non-goals (for now)

• Directory scanning
• Persistent local library across sessions
• Write-back / file modification