feat: navigate in plate terms

Opt into cce-ui's Tab traversal (Application::plate_navigation): Tab and
Shift+Tab walk the plates and wells in reading order, each lighting its own
rim; a press acts on a plate, a well opens for typing.

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

 src/main.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index 920917a..18abcdc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2485,6 +2485,11 @@ impl Application for DataEditorApp {
         }
     }
 
+    /// Tab walks the plates and wells (cce-ui's navigation in plate terms).
+    fn plate_navigation(&self) -> bool {
+        true
+    }
+
     fn handle_key_input(&mut self, event: &KeyEvent, needs_rebuild: &mut bool) -> Option<Self::Message> {
         self.ctrl_pressed = event.ctrl;
         self.ui_context.ctrl_pressed = event.ctrl;