Refactor Filament resources and models; add attribute casting in Group model, update navigation icons, and remove TeacherSeeder in favor of UserTableSeeder.

app/Filament/Resources/Groups/Tables/GroupsTable.php

@@ -14,11 +14,6 @@ class GroupsTable
     {
         return $table
             ->columns([
-                TextColumn::make('leaderTeacher.name')
-                    ->label('Topar başy')
-                    ->searchable()
-                    ->sortable(),
-
                 TextColumn::make('start_date')
                     ->label('Başlanýan senesi')
                     ->date()
@@ -29,6 +24,11 @@ class GroupsTable
                     ->date()
                     ->sortable(),
 
+                TextColumn::make('leaderTeacher.name')
+                    ->label('Topar başy')
+                    ->searchable()
+                    ->sortable(),
+
                 TextColumn::make('created_at')
                     ->dateTime()
                     ->sortable()