feat(bluetooth): add support for Healthkeep 280 smart scale

[danidemis]

This PR adds support for Healthkeep smart scales (OEM Icomon / Yolanda / Fitdays chipset family, my model is Healthkeep 280).

Protocol & Technical Details

• GATT Service UUID: 0xFFB0
• Write Characteristic (0xFFB1): Used to send the user profile initialization/handshake packet (AC 02 FB [SEX] [AGE] [HEIGHT] CC [CHECKSUM]) required to unlock impedance measurement.
• Notify Characteristic (0xFFB2): Handles live weight streaming updates during the weighing process.
• Indicate Characteristic (0xFFB3): Listens for the final measurement indication (0xA3), successfully extracting the stabilized weight, heart rate (BPM), and body impedance (Ohm).
• Body Composition: Integrates openScale's StandardImpedanceLib to automatically compute body fat, total body water, muscle mass, and bone mass based on the received impedance and user profile.

Testing & Changes

• Created a new handler file: HealthKeep280Handler.kt.
• Registered the handler in ScaleFactory.kt.
• Added a scale catalog fixture in ScaleCatalog.kt.
• Added a dedicated unit test (HealthKeep280HandlerTest.kt) to ensure correct byte-array parsing and validation.
• Tested successfully on a physical device.

I attach the nRF (ble-sharable.log) capture because problems on get btsnoop_hci.log .
ble-sharable.log