Just send messages via https://docs.micropython.org/en/latest/library/espnow.html to all devices via
broadcast address and display all messages that are send from other devices...

Some limitations: All devices must send on the same WiFi channel.

#90)

* Add support for LilyGo T-HMI board and initialize display and battery management

* Implement detection for LilyGO T-HMI touch screen

* Refactor LilyGO T-HMI initialization and update touch device configuration

* Remove t-hmi target configuration from build script and streamline OTA support handling

Add hardware support for M5Stack Core2 (ESP32-D0WDQ6-V3):

New files:
- drivers/power/axp192.py: AXP192 power management IC driver handling
  voltage regulation (DCDC1/3, LDO2/3), GPIO control (LCD/touch reset,
  speaker enable), battery monitoring via ADC, and charging control.
- mpos/board/m5stack_core2.py: Board initialization including ILI9342C
  display (SPI), FT6336U capacitive touch (I2C), NS4168 I2S speaker,
  SPM1423 PDM microphone, MPU6886 IMU, and AXP192-based battery
  voltage reading.

Modified files:
- mpos/main.py: Add Core2 detection via AXP192 I2C probe (0x34) in
  detect_board(). Guard ESP32-S3 specific GPIO probes (pins 10/11,
  39/38, 48/47) with chip variant check to prevent WDT reset on ESP32.

Hardware peripherals supported:
- Display: ILI9342C 320x240 via SPI (SCLK=18, MOSI=23, DC=15, CS=5)
- Touch: FT6336U via shared I2C host 0 (SDA=21, SCL=22, addr=0x38)
- Power: AXP192 via shared I2C host 0 (addr=0x34)
- Audio: NS4168 speaker (I2S: BCLK=12, LRCK=0, DATA=2)
- Mic: SPM1423 (PDM: CLK=0, DATA=34)
- IMU: MPU6886 via shared I2C host 0 (addr=0x68)
- Battery: Read via AXP192 ADC (no dedicated ADC pin needed)

All I2C devices share a single hardware I2C(0) controller. LCD reset
and backlight are controlled via AXP192 GPIO4 and DCDC3 respectively.

Tested on M5Stack Core2 (original version).

Signed-off-by: imliubo <[email protected]>
Co-authored-by: Thomas Farstrike <[email protected]>

* Fix desktop run: handle missing _webrepl module gracefully

The WebServer import chain (mpos/__init__.py → webserver.py →
webrepl_http.py) requires the _webrepl C module which is only
available on ESP32 builds. This causes an ImportError on desktop/Unix
systems, preventing the entire mpos package from loading.

Wrap the import in try/except so desktop builds can still run.
main.py already has a similar guard around WebServer.auto_start().

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* Add international number format setting

Add a system-wide number format preference to the Settings app,
allowing users to choose their preferred decimal and thousands
separators. Follows the TimeZone pattern with a NumberFormat
utility class that any app can import.

Available formats:
- 1,234.56 (US/UK)
- 1.234,56 (Europe)
- 1 234,56 (French)
- 1'234.56 (Swiss)
- 1_234.56 (Tech)
- 1234.56 / 1234,56 (No thousands separator)

New files:
- lib/mpos/number_format.py — NumberFormat class with format_number()
- tests/test_number_format.py — 14 unit tests

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Richard Taylor <[email protected]>
Co-authored-by: Claude Opus 4.6 <[email protected]>