style-audit: declare this surface's opt-out from the standard root plate

cce-ui's scripts/style-audit checks that every app stands on the
standard root plate; this crate is not a plate by design, and the
comment says why so the audit lists it as an opt-out rather than as
off-standard.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

 src/main.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index 75956dd..457afaa 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1008,6 +1008,8 @@ impl Application for GridApp {
         None
     }
 
+    // style-audit: opt-out the desktop grid overlay draws the compositor cells, not a window
+
     fn display_list(&mut self, size: LogicalSize, _scale: f64) -> Option<DisplayList> {
         let mut pc = PaintCtx::new();
         self.paint(&mut pc, size);