chore: update TODO.md

Author: dy-tea

TODO.md

@@ -11,6 +11,7 @@
 - Floating toplevels with mica are missing rounded border clip on their surface
 - Some layer surfaces with blur and a static position do not update the blur surface correctly (layer surface bar doesn't appear to track a toplevel behind it consistently; moving to an empty workspace from a non-empty workspace leaves behind some stale information in the blur surface)
 - Intel works perfectly but AMD has the following issues: gles2 non-protocol blur buffers render as black; vulkan has an abort when closing some toplevels, incorrectly clips surfaces with rounded borders and blur surfaces are missing
+- When shadow is enabled on a toplevel with rounded borders, the shadow seems to be clipped where the toplevel was clipped by the rounded border (either a layering or rendering issue)
 
 # Layout
 - Better tab grouping (see sway or Hyprland for reference)