handleSendToRadio
Sends a packet to the radio with retry support.
Write-failure policy: any non-cancellation exception from a failed write (after exhausting retryBleOperation retries) is treated as fatal to the current BLE session. Production logs show long-running sessions eventually failing writes with NotConnectedException after hundreds of successful writes — by that point the GATT handle is stale and retrying in-place cannot recover. Calling handleFailure forces a full GATT teardown + reconnect cycle, which is the only reliable recovery for a dead session. Transient single-write blips are absorbed by retryBleOperation's 3-attempt retry before reaching this catch.
Return
true when the current BLE profile generation accepted responsibility for the bounded write attempt. Delivery is confirmed later by the protocol, not by this result.
Parameters
The packet to send.