Fix product creation: auto-generate SKU, catch DB exceptions

- SKU is NOT NULL in the database but was nullable in wizard validation,
  causing a crash when submitted without a SKU value
- Auto-generate SKU (PRD-0001, SRV-0001, DIG-0001) when not provided
- Catch QueryException in both product forms to show friendly error
  instead of crashing on unique constraint violations
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Livewire/Inventory/CreateProductWizard.php

@@ -124,10 +124,12 @@ public function goToStep(int $step): void
     public function confirm(): void
     {
         try {
+            $sku = $this->sku ?: $this->generateSku();
+
             Product::create([
                 'name_ar' => $this->nameAr,
                 'name' => $this->name ?: null,
-                'sku' => $this->sku ?: null,
+                'sku' => $sku,
                 'barcode' => $this->barcode ?: null,
                 'category_id' => $this->categoryId,
                 'branch_id' => session('active_branch_id'),
@@ -147,9 +149,26 @@ public function confirm(): void
             $this->redirect(route('inventory.products'), navigate: true);
         } catch (DomainException $e) {
             session()->flash('error', $e->getMessage());
+        } catch (\Illuminate\Database\QueryException $e) {
+            if (str_contains($e->getMessage(), 'unique')) {
+                session()->flash('error', 'رمز المنتج (SKU) مستخدم بالفعل');
+            } else {
+                session()->flash('error', 'حدث خطأ أثناء حفظ المنتج: ' . $e->getMessage());
+            }
         }
     }
 
+    private function generateSku(): string
+    {
+        $prefix = match ($this->type) {
+            'service' => 'SRV',
+            'digital' => 'DIG',
+            default => 'PRD',
+        };
+        $count = Product::withoutGlobalScopes()->count() + 1;
+        return $prefix . '-' . str_pad($count, 4, '0', STR_PAD_LEFT);
+    }
+
     public function render()
     {
         return view('livewire.inventory.create-product-wizard');

app/Livewire/Inventory/ProductForm.php

@@ -67,7 +67,7 @@ public function rules(): array
         return [
             'name_ar' => 'required|string|max:255',
             'name' => 'nullable|string|max:255',
-            'sku' => ['required', 'string', 'max:50', $uniqueSku],
+            'sku' => ['nullable', 'string', 'max:50', $uniqueSku],
             'barcode' => 'nullable|string|max:50',
             'category_id' => 'nullable|exists:product_categories,id',
             'type' => 'required|in:physical,digital,service',
@@ -113,7 +113,7 @@ public function save(): void
             $data = [
                 'name_ar' => $this->name_ar,
                 'name' => $this->name ?: null,
-                'sku' => $this->sku,
+                'sku' => $this->sku ?: $this->generateSku(),
                 'barcode' => $this->barcode ?: null,
                 'category_id' => $this->category_id,
                 'type' => $this->type,
@@ -140,9 +140,26 @@ public function save(): void
             $this->redirect(route('inventory.products'), navigate: true);
         } catch (DomainException $e) {
             session()->flash('error', $e->getMessage());
+        } catch (\Illuminate\Database\QueryException $e) {
+            if (str_contains($e->getMessage(), 'unique')) {
+                session()->flash('error', __('رمز المنتج (SKU) مستخدم بالفعل'));
+            } else {
+                session()->flash('error', __('حدث خطأ أثناء حفظ المنتج'));
+            }
         }
     }
 
+    private function generateSku(): string
+    {
+        $prefix = match ($this->type) {
+            'service' => 'SRV',
+            'digital' => 'DIG',
+            default => 'PRD',
+        };
+        $count = Product::withoutGlobalScopes()->count() + 1;
+        return $prefix . '-' . str_pad($count, 4, '0', STR_PAD_LEFT);
+    }
+
     public function render()
     {
         return view('livewire.inventory.product-form', [