Gradient tool does not fade into transparency

Summary:

The gradient tool produces a 'solid gradient' instead of fading into transparency. Introduced in inkscape@87dff623. Switching to a 'Gradient' using the Fill&Stroke dialog also has the same regression.

Steps to reproduce:

• open Inkscape
• Create an object with a fill
• Add a gradient using the gradient tool

What happened?

Object has a gradient, but it isn't obvious

What should have happened?

Same behaviour as 1.4.2 - gradient fading into transparency.

Version info

Inkscape 1.5-dev (b56c385615, 2025-09-26, custom)

                      Compile  (Run)
    GLib version:     2.84.4
    GTK version:      4.18.6 (4.18.6)
    glibmm version:   2.83.1
    gtkmm version:    4.18.0
    libxml2 version:  2.12.10
    libxslt version:  1.1.43
    Cairo version:    1.18.2 (1.18.2)
    Pango version:    1.56.4 (1.56.4)
    HarfBuzz version: 10.4.0 (10.4.0)
    Poppler version:  25.02.0

    OS version:       Fedora Linux 42 (Workstation Edition)