Sequence diagram: Plugin crash during playback

sequenceDiagram
    participant User
    participant Shell as Svelte Shell
    participant Engine as Playback Engine
    participant RT as Plugin Runtime

    User->>Shell: Press play on queue item B
    Shell->>Engine: invoke("play_track", { plugin_id, content_id, metadata })
    Engine->>RT: stream(plugin_id, content_id)
    RT->>RT: Plugin process exits unexpectedly
    RT-->>Engine: PluginError::Crash
    Engine-->>Shell: emit("playback_error", { error: "Stream unavailable" })
    Engine->>Engine: Auto-advance to next queue item
    Engine-->>Shell: emit("track_changed", next_track)
    Engine->>RT: stream(next_plugin_id, next_content_id)
    RT-->>Engine: StreamInfo
    Engine->>Engine: Begin playback
    Shell-->>User: Show toast "Track unavailable, skipping"