The user does not see a failure when a Move action fails

[dhalbert]

If the user does a Move which fails (say, due to a read-only filesystem), there is no error indication.

To reproduce: Connect over the BLE workflow with CIRCUITPY mounted over USB, so the filesystem is read-only to CircuitPython, then move any file. The device returns STATUS_ERROR, the client rejects, and the dialog does nothing. Unplugging USB and powering the board separately makes the same move succeed.

Suggested fix details

_handleMoveButton() in js/common/file_dialog.js treats a failed move as a falsy return value:

} else if (!(await this._showBusy(this._fileHelper.move(oldPath, newPath)))) {
    this._showMessage(`Error moving ${oldPath} to ${newPath}. Make sure the file you are moving exists.`);
    errors = true;
}

But move() rejects on failure rather than returning false. processMoveStatus() in @adafruit/ble-file-transfer-js calls this._reject("Unable to move file") when the device answers STATUS_ERROR, and showBusy() is try/finally with no catch, so the rejection propagates out of the handler. _showMessage() never runs, the loop over selected files aborts, and _openFolder(newFolder) never runs.

By contrast, _handleRenameButton(), the next function in the file, already wraps its move() call in try/catch.

To fix, catch the rejection and show its message, which is more specific than the current text:

} else {
    try {
        await this._showBusy(this._fileHelper.move(oldPath, newPath));
    } catch (e) {
        this._showMessage(`Error moving ${oldPath} to ${newPath}: ${e}`);
        errors = true;
    }
}

[originally written by Claude, greatly pruned and edited for clarity by @dhalbert]