* BIG refactor: 'board' and 'radio' objects now defined in 'target.h/.cpp'

* mesh::RTCClock class moved to MeshCore.h

variants/xiao_s3_wio/platformio.ini

@@ -4,6 +4,7 @@ board = seeed_xiao_esp32s3
 board_check = true
 board_build.mcu = esp32s3
 build_flags = ${esp32_base.build_flags}
+  -I variants/xiao_s3_wio
   -D SEEED_XIAO_S3
   -D P_LORA_DIO_1=39
   -D P_LORA_NSS=41
@@ -19,6 +20,8 @@ build_flags = ${esp32_base.build_flags}
   -D WRAPPER_CLASS=CustomSX1262Wrapper
   -D LORA_TX_POWER=22
   -D SX126X_RX_BOOSTED_GAIN=1
+build_src_filter = ${esp32_base.build_src_filter}
+  +<../variants/xiao_s3_wio>
 
 [env:Xiao_S3_WIO_Repeater]
 extends = Xiao_S3_WIO