Merge remote-tracking branch 'review/observer-firmware' into keymindCascade

# Conflicts:
#	.github/workflows/build-observer-firmwares.yml
#	.gitignore
#	MQTT_IMPLEMENTATION.md
#	MQTT_INTERNALS.md
#	README.md
#	STABILITY_TESTABILITY_HANDOFF.md
#	docs/cli_commands.md
#	examples/companion_radio/MyMesh.cpp
#	examples/simple_repeater/MyMesh.cpp
#	examples/simple_repeater/UITask.cpp
#	examples/simple_room_server/MyMesh.cpp
#	examples/simple_room_server/UITask.cpp
#	examples/simple_sensor/SensorMesh.cpp
#	platformio.ini
#	scripts/generate_webconfig_html.py
#	scripts/webconfig_mock_server.py
#	src/helpers/CommonCLI.cpp
#	src/helpers/CommonCLI.h
#	src/helpers/JWTHelper.cpp
#	src/helpers/MQTTDefaults.h
#	src/helpers/MQTTMessageBuilder.cpp
#	src/helpers/MQTTPayloadBuilder.h
#	src/helpers/MQTTPresets.h
#	src/helpers/bridges/MQTTBridge.h
#	src/helpers/esp32/WebConfigServer.cpp
#	src/helpers/esp32/WebConfigServer.h
#	src/helpers/ui/SH1106Display.cpp
#	variants/lilygo_tbeam_SX1262/platformio.ini
#	variants/lilygo_tbeam_SX1276/platformio.ini
#	variants/lilygo_tlora_v2_1/platformio.ini
#	variants/thinknode_m7/platformio.ini
#	webui/index.html

src/helpers/ui/SH1106Display.cpp

@@ -29,6 +29,7 @@ bool SH1106Display::begin()
   // preferred alternate explicitly; otherwise try the other address in the
   // pair. Always run the Adafruit init so its buffer and device objects exist,
   // even when no panel answers the probe.
+  _initialized = false;
   uint8_t addr = 0;
   if (i2c_probe(Wire, DISPLAY_ADDRESS)) {
     addr = DISPLAY_ADDRESS;
@@ -43,17 +44,23 @@ bool SH1106Display::begin()
     addr = DISPLAY_ADDRESS ^ 1;
   }
   bool ok = display.begin(addr ? addr : DISPLAY_ADDRESS, true);
-  return addr != 0 && ok;
+  _initialized = addr != 0 && ok;
+  return _initialized;
 }
 
 void SH1106Display::turnOn()
 {
+  if (!_initialized) return;
   display.oled_command(SH110X_DISPLAYON);
   _isOn = true;
 }
 
 void SH1106Display::turnOff()
 {
+  if (!_initialized) {
+    _isOn = false;
+    return;
+  }
   display.oled_command(SH110X_DISPLAYOFF);
   _isOn = false;
 }