Fix cart checkout flow issues

- Store Stripe checkout session ID on cart before redirect
- Allow GET requests to checkout route for post-login redirects
- Fix guest cart transfer to only merge into active (non-completed) carts

Author: shanerbaner82

app/Http/Controllers/CartController.php

@@ -216,6 +216,8 @@ public function checkout(Request $request): RedirectResponse
         try {
             $session = $this->createMultiItemCheckoutSession($cart, $user);
 
+            $cart->update(['stripe_checkout_session_id' => $session->id]);
+
             return redirect($session->url);
         } catch (\Exception $e) {
             Log::error('Cart checkout failed', [
@@ -240,7 +242,8 @@ public function success(Request $request): View|RedirectResponse
                 ->with('error', 'Invalid checkout session. Please try again.');
         }
 
-        // Cart will be marked as completed by the webhook when payment is confirmed
+        // Cart will be marked as completed by the webhook after licenses are created
+
         return view('cart.success', [
             'sessionId' => $sessionId,
         ]);

app/Services/CartService.php

@@ -150,7 +150,9 @@ public function transferGuestCartToUser(User $user): ?Cart
             return null;
         }
 
-        $userCart = Cart::where('user_id', $user->id)->first();
+        $userCart = Cart::where('user_id', $user->id)
+            ->whereNull('completed_at')
+            ->first();
 
         if ($userCart) {
             // Merge guest cart items into user cart

routes/web.php

@@ -284,7 +284,7 @@
     Route::delete('cart/bundle/{bundle:slug}', [CartController::class, 'removeBundle'])->name('cart.bundle.remove');
     Route::delete('cart/clear', [CartController::class, 'clear'])->name('cart.clear');
     Route::get('cart/count', [CartController::class, 'count'])->name('cart.count');
-    Route::post('cart/checkout', [CartController::class, 'checkout'])->name('cart.checkout');
+    Route::match(['get', 'post'], 'cart/checkout', [CartController::class, 'checkout'])->name('cart.checkout');
     Route::get('cart/success', [CartController::class, 'success'])->name('cart.success')->middleware('auth');
     Route::get('cart/status/{sessionId}', [CartController::class, 'status'])->name('cart.status')->middleware('auth');
     Route::get('cart/cancel', [CartController::class, 'cancel'])->name('cart.cancel');