Merge upstream companion-v1.17.0 (CAD) into power-saving

Adopts hardware Channel Activity Detection (wired into
RadioLibWrapper::isChannelActive() alongside our RSSI-threshold check
and RX duty-cycle power-save), MCU temperature telemetry, LR2021
standby workaround, DISPLAY_SCALE/FLIP overrides, NRF52Board
shutdownPeripherals() refactor, and misc upstream fixes.

Declines upstream's ConfigSerializer-based NodePrefs rewrite,
MultiSerialInterface/interface_manager, and UIColor palette system —
each would have broken large parts of the Solo-specific feature set
(NodePrefs fields, per-variant single serial_interface, enum-based
DisplayDriver::Color). Flagged as candidate follow-up migrations, not
permanent no's.

Also fixes several pre-existing bugs surfaced while chasing silent
merge breaks (stale newMsg() override signature in ui-tiny/ui-orig,
dead UIEventType::newContactMessage case, missing ContactsIterator
init), bumps FIRMWARE_VERSION/MESHCORE_VERSION to 1.17, and fixes a
missing <cstdlib> include that broke the native ConfigSerializer unit
tests.

Verified via 13+ pio run builds across ESP32/nRF52, all 3 companion UI
variants, and 7 display drivers, plus the full native unit test suite
(33/33 passing).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

variants/lilygo_techo_lite/TechoBoard.cpp

@@ -6,7 +6,7 @@
 #ifdef LILYGO_TECHO
 
 void TechoBoard::begin() {
-  NRF52Board::begin();
+  NRF52BoardDCDC::begin();
 
   // Configure battery measurement control BEFORE Wire.begin()
   // to ensure P0.02 is not claimed by another peripheral

variants/lilygo_techo_lite/TechoBoard.h

@@ -31,7 +31,9 @@ public:
   }
   #endif
 
-  void powerOff() override {
+  void shutdownPeripherals() override {
+    NRF52Board::shutdownPeripherals();
+
     digitalWrite(PIN_VBAT_MEAS_EN, LOW);
     #ifdef LED_RED
     digitalWrite(LED_RED, LOW);
@@ -48,6 +50,5 @@ public:
     #ifdef PIN_PWR_EN
     digitalWrite(PIN_PWR_EN, LOW);
     #endif
-    sd_power_system_off();
   }
 };

variants/lilygo_techo_lite/platformio.ini

@@ -15,6 +15,7 @@ build_flags = ${nrf52_base.build_flags}
   -D SX126X_DIO3_TCXO_VOLTAGE=3.0 ;https://github.com/Xinyuan-LilyGO/T-Echo-Lite/issues/14
   -D SX126X_CURRENT_LIMIT=140
   -D SX126X_RX_BOOSTED_GAIN=1
+  -D SX126X_USE_REGULATOR_LDO=1
   -D P_LORA_TX_LED=LED_GREEN
   -D DISABLE_DIAGNOSTIC_OUTPUT
   -D ENV_INCLUDE_GPS=1
@@ -72,7 +73,7 @@ build_flags =
   -D AUTO_SHUTDOWN_MILLIVOLTS=3300
   -D ENV_USE_TCA8418=1
   -D FIRMWARE_SOLO_BUILD=1
-  -D MESHCORE_VERSION='"1.16"'
+  -D MESHCORE_VERSION='"1.17"'
   -D ENABLE_SCREENSHOT
   -Os
 build_src_filter = ${LilyGo_T-Echo-Lite.build_src_filter}
@@ -131,7 +132,7 @@ build_flags =
   ; -D MESH_DEBUG=1
   -D AUTO_SHUTDOWN_MILLIVOLTS=3300
   -D FIRMWARE_SOLO_BUILD=1
-  -D MESHCORE_VERSION='"1.16"'
+  -D MESHCORE_VERSION='"1.17"'
 build_src_filter = ${LilyGo_T-Echo-Lite.build_src_filter}
   +<helpers/nrf52/SerialBLEInterface.cpp>
   +<../examples/companion_radio/*.cpp>
@@ -215,6 +216,7 @@ build_flags =
   -D MAX_GROUP_CHANNELS=40
   -D UI_RECENT_LIST_SIZE=9
   -D AUTO_SHUTDOWN_MILLIVOLTS=3300
+  -D ENABLE_USB_INTERFACE
   ; -D MESH_PACKET_LOGGING=1
   ; -D MESH_DEBUG=1
 build_src_filter = ${nrf52_base.build_src_filter}