Enhance Group and Document resources; add leader and helper teacher relationships, update navigation icons, and adjust navigation sorting.

app/Models/Group.php

@@ -3,11 +3,12 @@
 namespace App\Models;
 
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 
 /**
- * @property string $name
  * @property date $start_date
  * @property date $end_date
  * @property Pilgrim[] $pilgrims
@@ -22,4 +23,14 @@ class Group extends Model
     {
         return $this->hasMany(Pilgrim::class);
     }
+
+    public function leaderTeacher(): BelongsTo
+    {
+        return $this->belongsTo(Teacher::class, 'leader_teacher_id');
+    }
+
+    public function helperTeachers(): BelongsToMany
+    {
+        return $this->belongsToMany(Teacher::class, 'group_teacher');
+    }
 }