fix all issues

app/Models/ConfigurationModel.php

@@ -22,11 +22,13 @@ class ConfigurationModel extends Model
      */
     public function getConfigValueByKey(string $key)
     {
-        // Deterministic read in case historical duplicates exist
-        $result = $this->where('config_key', $key)
+        // Use a fresh builder to avoid stale state from shared model builder.
+        $builder = $this->db->table($this->table);
+        $result = $builder->where('config_key', $key)
             ->orderBy('id', 'DESC')
-            ->first();
-        return $result ? $result['config_value'] : null;
+            ->get(1)
+            ->getRowArray();
+        return $result['config_value'] ?? null;
     }
 
     /**

app/Models/SubjectCurriculumModel.php

@@ -27,6 +27,7 @@ class SubjectCurriculumModel extends Model
         return $this->where('class_id', $classId)
             ->where('subject', $subject)
             ->orderBy('unit_number', 'ASC')
+            ->orderBy("CAST(SUBSTRING_INDEX(chapter_name, '.', 1) AS UNSIGNED)", 'ASC', false)
             ->orderBy('chapter_name', 'ASC')
             ->findAll();
     }