I claim the ornamental design for a furniture fret, as shown and described.
FIG. 1 is two-dimensional plan view of my new design as applied to a chair back.
FIG. 2 is a two-dimensional plan view of my new design as applied to a table pedestal.
FIG. 3 is a two-dimensional plan view of my new design as applied to a bookcase; and,
FIG. 4 is a two-dimensional plan view of my new design as applied to a chair.
The views of the furniture fret not shown form no part of the claimed design. The dash-dash lines in the Figures represent features and environmental elements that form no part of the claimed design.