完整性更新

现在已经实现了大部分基础功能

docs/db/seed-data.md

@@ -59,6 +59,12 @@ Demonstrates the new **JSON Structure** field (`exams.structure`).
     ]
     ```
 
+### 2.5 Classes / Enrollment / Schedule
+Seeds the teacher class management domain.
+*   **Classes**: Creates at least one class owned by a teacher user.
+*   **Enrollments**: Links students to classes via `class_enrollments` (default status: `active`).
+*   **Schedule**: Populates `class_schedule` with weekday + start/end times for timetable validation.
+
 ## 3. How to Run
 
 ### Prerequisites