Gapless playback — test audio artifacts

Audio artifacts backing the gapless-playback write-up. Not software — these are
test outputs, published here so the article can link to playable files and so the
result can be re-verified independently.

Generated by packages/kalinka-server/tests/test_gapless_playback.py, which plays
two FLAC files back to back through the real audio graph and captures every frame
the ALSA emitter writes.

Listen

file	what it is
captured-joined.wav	the two tracks played back to back (3 s) — one continuous 441.5 Hz tone
captured-with-gap.wav	the same output with 3 ms of silence spliced in at 1.5 s, for comparison
reference-joined.wav	the source tone the two halves were cut from

Re-verify

a.flac and b.flac are the exact inputs that were queued; captured-joined.raw
is what the player wrote to the ALSA device. verify.sh decodes the inputs with
the reference flac decoder, concatenates them and compares — no Python, none of
the project's code in the measurement chain:

sha256sum reference-from-flac-cli.raw captured-joined.raw
482bd54a14ee9ce215008b4ad57e14bcdbcc36167ec2fe6aabb73a0b6828d5d0  reference-from-flac-cli.raw
482bd54a14ee9ce215008b4ad57e14bcdbcc36167ec2fe6aabb73a0b6828d5d0  captured-joined.raw

Signal: 441.5 Hz sine, 44.1 kHz, 16-bit stereo, −6 dBFS, cut in half at frame 66,150.