fedac/native: add ATTcifXGXi to wifi presets, ship piano samples in OTA
WiFi: register ATTcifXGXi as a fourth preset across the three sources of
truth (kernel auto-connect fallback, macOS flasher, Linux media layout).
Piano: build-and-flash-initramfs.sh (the path ac-os upload runs) was
missing the /samples/piano/*.raw copy block — recent OTAs shipped without
the piano bank, so notepat's piano voice was silent on device. Ported
the block from build-and-flash.sh.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>