The drawcursor glyph's ink spanned the full 1000-unit em (0..1000 x,
-150..850 y), so the plugin's square crop sliced the ring flat on all
four sides at every rendered size. Rescaled the outline to 84% about
its center in both the TTF and the fluttericon session config, leaving
~8% margin per side for antialiasing. Design is otherwise unchanged.