Show only upcoming Classroom to-dos.

Filter fetched to-dos to exclude past-due and undated items so the schedule surfaces only upcoming work.

Made-with: Cursor

classroom_app/Google/GoogleClassroomClient.swift

@@ -56,7 +56,13 @@ final class GoogleClassroomClient {
             }
         }
 
-        // Keep only items with a due date near-term first; undated items at end.
+        let now = Date()
+        todos = todos.filter {
+            guard let due = $0.dueDate else { return false }
+            return due >= now
+        }
+
+        // Keep upcoming items sorted by nearest due date first.
         todos.sort {
             switch ($0.dueDate, $1.dueDate) {
             case let (a?, b?):