fix inventory

app/Models/InventoryItem.php

@@ -30,6 +30,17 @@ class InventoryItem extends BaseModel
         'needs_repair_qty',
         'need_replace_qty',
         'cannot_find_qty',
+        // Supplier/reorder fields
+        'preferred_supplier_id',
+        'last_purchase_price',
+        'average_unit_cost',
+        'reorder_point',
+        'reorder_quantity',
+        'lead_time_days',
+        // Barcode/QR fields
+        'barcode',
+        'qr_code',
+        'asset_tag',
     ];
 
     protected $casts = [
@@ -41,6 +52,13 @@ class InventoryItem extends BaseModel
         'needs_repair_qty'   => 'integer',
         'need_replace_qty'   => 'integer',
         'cannot_find_qty'    => 'integer',
+
+        'preferred_supplier_id' => 'integer',
+        'last_purchase_price'   => 'decimal:2',
+        'average_unit_cost'     => 'decimal:2',
+        'reorder_point'         => 'integer',
+        'reorder_quantity'      => 'integer',
+        'lead_time_days'        => 'integer',
     ];
 
     /* Optional relationships */
@@ -48,4 +66,25 @@ class InventoryItem extends BaseModel
     {
         return $this->belongsTo(InventoryCategory::class, 'category_id');
     }
+
+    public function preferredSupplier()
+    {
+        return $this->belongsTo(Supplier::class, 'preferred_supplier_id');
+    }
+
+    public function movements()
+    {
+        return $this->hasMany(InventoryMovement::class, 'item_id');
+    }
+
+    public function scopeLowStock($query)
+    {
+        return $query->whereNotNull('reorder_point')
+            ->whereColumn('quantity', '<=', 'reorder_point');
+    }
+
+    public function scopeOutOfStock($query)
+    {
+        return $query->where('quantity', '<=', 0);
+    }
 }

app/Models/InventoryMovement.php

@@ -23,6 +23,13 @@ class InventoryMovement extends BaseModel
         'teacher_id',
         'student_id',
         'class_section_id',
+        // Audit/correction fields
+        'voided_at',
+        'voided_by',
+        'void_reason',
+        'corrects_movement_id',
+        'source_type',
+        'source_id',
     ];
 
     protected $casts = [
@@ -32,8 +39,23 @@ class InventoryMovement extends BaseModel
         'teacher_id'      => 'integer',
         'student_id'      => 'integer',
         'class_section_id'=> 'integer',
+        'voided_by'       => 'integer',
+        'corrects_movement_id' => 'integer',
+        'source_id'       => 'integer',
+        'voided_at'       => 'datetime',
     ];
 
+    /* Scopes */
+    public function scopeNotVoided($query)
+    {
+        return $query->whereNull('voided_at');
+    }
+
+    public function scopeVoided($query)
+    {
+        return $query->whereNotNull('voided_at');
+    }
+
     /* Optional relationships */
     public function item()
     {
@@ -59,4 +81,19 @@ class InventoryMovement extends BaseModel
     {
         return $this->belongsTo(ClassSection::class, 'class_section_id');
     }
+
+    public function voidedBy()
+    {
+        return $this->belongsTo(User::class, 'voided_by');
+    }
+
+    public function correctsMovement()
+    {
+        return $this->belongsTo(self::class, 'corrects_movement_id');
+    }
+
+    public function corrections()
+    {
+        return $this->hasMany(self::class, 'corrects_movement_id');
+    }
 }

app/Models/PurchaseOrderItem.php

@@ -12,6 +12,7 @@ class PurchaseOrderItem extends BaseModel
     protected $fillable = [
         'purchase_order_id',
         'supply_id',
+        'inventory_item_id',
         'description',
         'quantity',
         'received_qty',