Handle USB device disconnection during flashing

[ashishsinghbora]

Problem Statement

A user may physically remove the USB device while FlashCore is writing.

The application must detect this situation and never report a false successful flash.

Proposed Solution / Enhancement

Detect USB device removal during an active flash.

When disconnection occurs:

• Stop pending operations.
• Cancel the flash safely.
• Release USB resources.
• Update application state.
• Report a clear failure to the user.

Add automated tests using a fault-injecting BlockDevice where possible.

Architectural Layer Impacted

USB Layer / Flash Engine / Android Integration

Alternatives Considered

Ignoring disconnection errors could leave the target partially written while the UI reports success.