Add Ladill POS v1 — register, Pay checkout, and commerce links.

Staff-facing counter register at pos.ladill.com with catalog cart, cash and
MoMo/card checkout via Ladill Pay, CRM timeline/import, invoice prefill, and
Merchant catalog import.

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

app/Http/Controllers/Pos/SaleController.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace App\Http\Controllers\Pos;
+
+use App\Http\Controllers\Controller;
+use App\Http\Controllers\Pos\Concerns\ScopesToAccount;
+use App\Models\PosSale;
+use App\Services\CrossApp\CrossAppLinkService;
+use App\Services\Pos\PosSaleService;
+use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
+use Illuminate\View\View;
+use RuntimeException;
+
+class SaleController extends Controller
+{
+    use ScopesToAccount;
+
+    public function __construct(
+        private PosSaleService $sales,
+        private CrossAppLinkService $links,
+    ) {}
+
+    public function index(Request $request): View
+    {
+        $sales = PosSale::owned($this->ownerRef($request))
+            ->with('lines')
+            ->latest()
+            ->paginate(25)
+            ->withQueryString();
+
+        return view('pos.sales.index', compact('sales'));
+    }
+
+    public function show(Request $request, PosSale $sale): View
+    {
+        $this->authorizeOwner($request, $sale);
+        $sale->load('lines', 'location');
+
+        $invoiceUrl = $sale->isPaid()
+            ? $this->links->invoiceFromSale($sale)
+            : null;
+
+        return view('pos.sales.show', compact('sale', 'invoiceUrl'));
+    }
+
+    public function callback(Request $request, PosSale $sale): RedirectResponse
+    {
+        $reference = trim((string) $request->query('reference', $sale->payment_reference ?? ''));
+
+        if ($reference === '') {
+            return redirect()->route('pos.sales.show', $sale)->with('error', 'Missing payment reference.');
+        }
+
+        try {
+            $sale = $this->sales->completePayCheckout($reference);
+        } catch (RuntimeException $e) {
+            return redirect()->route('pos.sales.show', $sale)->with('error', $e->getMessage());
+        }
+
+        return redirect()
+            ->route('pos.sales.show', $sale)
+            ->with('success', 'Payment received.');
+    }
+}