47fbc09fea
ADCCONTROL6 (reg 0x0E) reset default = 0x30 which has ADCSMUTE=1 (bit5) — ADC output muted by default. Writing 0x00 unmutes. Without this, ADCINSEL=0x50 (LIN2) is selected but the signal is suppressed at the ADC output stage → peak=0. ADCPOWER (reg 0x03) changed from 0x09 (intermediate Espressif open state) to 0x00 (full power-up: all power-down bits cleared). Value 0x09 = bits 0+3 set (ADCPD_L + MICBIAS_PD) — MICBIAS_PD in particular means the internal microphone bias is powered off, which can starve the SLIC line-in path. 0x00 is the correct end state for recording mode per Espressif esp8388_start(ES_MODULE_ADC) reference. sdkconfig.defaults: add CONFIG_PLIP_HOOK_GPIO=23 / CONFIG_PLIP_HOOK_ACTIVE_HIGH=y as explicit defaults so clean builds use the SLIC SHK pin without menuconfig.