OOTB playback froze (seekbar advancing, no audio) on hosts where the
configured backend was not usable — e.g. PipeWire as the Linux default but
`pactl` absent (minimal Debian/Ubuntu). "Auto" (a null backend_type) fell
through to a legacy CPAL path that forced the track rate onto the shared
default device, producing a suspended/silent stream and leaving a
process-wide stuck audio handle that survived Reset.
- Add a cross-platform "System" backend (CpalDefaultBackend now on Linux
too): opens the OS default output at its negotiated rate with rodio
resampling and an explicit ~100ms CPAL buffer (MixerDeviceSink has zero
internal buffering, so the bare default underran and stayed suspended).
Shared, no exclusivity, no `pactl` — mixes with other apps like any
normal player.
- Make System the OOTB default and what Reset lands on; seed it on first
run. Drop the per-startup #375 NULL->PipeWire backfill migration.
- Resolve a null backend_type to System in the player so the legacy CPAL
path is never reached (covers legacy installs and headless callers).
- "Auto" in Settings is now a resolve-and-set action: it picks the best
available backend (PipeWire if available, else System), stores that
concrete value and updates the dropdown + device picker, so backend_type
is never null.
- Explicit PipeWire (DAC passthrough) and ALSA Direct (exclusive) configs
are untouched and remain bit-perfect.
cc
vicrodh
a0051ab513