Allow cancelling and deleting pending POS sales

On a sale's detail page, unpaid sales (retail or restaurant) can now be
cancelled or deleted:
- Cancel (pending only) marks it cancelled and frees its table / clears it from
  the kitchen (PosSaleService::cancelSale).
- Delete removes the sale and cascades its lines, modifiers and payments, freeing
  the table first (deleteSale). Paid sales are protected — they can't be deleted.
Status badge now distinguishes cancelled/failed. Covered by PosRestaurantTest.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/Http/Controllers/Pos/SaleController.php

@@ -44,6 +44,32 @@ class SaleController extends Controller
         return view('pos.sales.show', compact('sale', 'invoiceUrl'));
     }
 
+    public function cancel(Request $request, PosSale $sale): RedirectResponse
+    {
+        $this->authorizeOwner($request, $sale);
+
+        try {
+            $this->sales->cancelSale($sale);
+        } catch (RuntimeException $e) {
+            return back()->with('error', $e->getMessage());
+        }
+
+        return redirect()->route('pos.sales.show', $sale)->with('success', 'Sale cancelled.');
+    }
+
+    public function destroy(Request $request, PosSale $sale): RedirectResponse
+    {
+        $this->authorizeOwner($request, $sale);
+
+        try {
+            $this->sales->deleteSale($sale);
+        } catch (RuntimeException $e) {
+            return back()->with('error', $e->getMessage());
+        }
+
+        return redirect()->route('pos.sales.index')->with('success', 'Sale deleted.');
+    }
+
     public function callback(Request $request, PosSale $sale): RedirectResponse
     {
         $reference = trim((string) $request->query('reference', $sale->payment_reference ?? ''));

app/Services/Pos/PosSaleService.php

@@ -446,6 +446,33 @@ class PosSaleService
         return $sale->fresh('lines');
     }
 
+    /** Cancel a pending sale/ticket — frees its table and clears it from the kitchen. */
+    public function cancelSale(PosSale $sale): void
+    {
+        if ($sale->status !== PosSale::STATUS_PENDING) {
+            throw new RuntimeException('Only pending sales can be cancelled.');
+        }
+
+        $sale->forceFill(['status' => PosSale::STATUS_CANCELLED])->save();
+        $this->closeTicket($sale);
+    }
+
+    /** Permanently delete an unpaid sale (and its lines, modifiers, payments). */
+    public function deleteSale(PosSale $sale): void
+    {
+        if ($sale->status === PosSale::STATUS_PAID) {
+            throw new RuntimeException('Paid sales cannot be deleted.');
+        }
+
+        if ($sale->table_id) {
+            PosTable::where('id', $sale->table_id)
+                ->where('current_sale_id', $sale->id)
+                ->update(['status' => PosTable::STATUS_FREE, 'current_sale_id' => null]);
+        }
+
+        $sale->delete();
+    }
+
     /**
      * Close a ticket once it's settled: free its table and mark kitchen done.
      */