fix: set period=1024 for sample-accurate capture timing
ALSA defaults (period=32768 = 682ms) caused massive timing drift.
Period=1024 gives ~21ms latency. The EIO root causes (HDMI open,
6-period playback, boot mixer) are all fixed so this should work now.
Removed first-chunk skip hack — with 21ms periods the direct write
path is precise enough.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>