feat(schedule): add course table screens and navigation

Add complete schedule functionality including:
- Schedule screen with weekly course table view
- Course detail screen with transparent modal presentation
- New ScheduleStack navigator integrated into main tab bar
- Schedule service for API interactions
- Type definitions for course entities

Also includes bug fixes for group invite/request handlers
to include required groupId parameter.

internal/model/init.go

@@ -143,6 +143,9 @@ func autoMigrate(db *gorm.DB) error {
 
 		// 自定义表情
 		&UserSticker{},
+
+		// 课表
+		&ScheduleCourse{},
 	)
 	if err != nil {
 		return err