OTAFIX 2.4.1 Preview 1 - USB-first recovery

Preview of OTAFIX 2.4.1 for USB-first recovery testing.

Changes since OTAFIX 2.4

• When no valid application is present, briefly offers USB CDC/UF2 and selects it only after host enumeration.
• Falls back immediately to BLE without VBUS, or after 3 seconds when VBUS is power-only or unconfigured.
• Releases the direct POWER interrupt before enabling the SoftDevice for BLE fallback.
• Services an inherited watchdog during delta OTA and USB probing.

Intended validation

• After a full erase and bootloader flash, a connected computer can install MeshCore over USB.
• Without an active USB data host, a phone can install MeshCore over BLE.

Validation

• Heltec T096 (ST7735S) and T114 (ST7789) CMake builds pass.
• The complete board release matrix and artifacts are generated by GitHub Actions.

This is a preview release intended for hardware testing.