fix: voice off by default, poweroff from first run, udhcpc path search
- Keystroke TTS disabled by default (voice_off=1)
- Init script handles exit code 0/2 from first run (not just crash loop)
- udhcpc searches /sbin, /bin, /usr/bin + passes default.script path
- Better DHCP log messages
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>