Initial Ladill Care release.

Healthcare management app: patients, appointments, consultations, lab,
pharmacy inventory, billing, and reports at care.ladill.com.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Models/DrugBatch.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Models;
+
+use App\Models\Concerns\BelongsToOwner;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class DrugBatch extends Model
+{
+    use BelongsToOwner;
+
+    protected $table = 'care_drug_batches';
+
+    protected $fillable = [
+        'owner_ref', 'drug_id', 'batch_number', 'expiry_date',
+        'quantity_on_hand', 'cost_minor', 'received_at',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'expiry_date' => 'date',
+            'received_at' => 'datetime',
+        ];
+    }
+
+    public function drug(): BelongsTo
+    {
+        return $this->belongsTo(Drug::class, 'drug_id');
+    }
+
+    public function dispensingRecords(): HasMany
+    {
+        return $this->hasMany(DispensingRecord::class, 'drug_batch_id');
+    }
+
+    public function isExpired(): bool
+    {
+        return $this->expiry_date !== null && $this->expiry_date->isPast();
+    }
+}