Surface PresentPaywall errors in UI, add errorLabel field

- Show errors in a visible errorLabel Text element instead of only
  Debug.LogError, so Maestro can capture failures in screenshots
- Update setup instructions with new ErrorLabel wiring step

Made-with: Cursor

Author: ajpallares

e2e-tests/MaestroTestApp/Assets/Scripts/MaestroTestApp.cs

@@ -9,6 +9,7 @@ public class MaestroTestApp : Purchases.UpdatedCustomerInfoListener
     public GameObject testCasesScreen;
     public GameObject purchaseScreen;
     public Text entitlementsLabel;
+    public Text errorLabel;
 
     private Purchases purchases;
 
@@ -22,6 +23,11 @@ void Start()
         purchases.SetLogLevel(Purchases.LogLevel.Verbose);
         purchases.listener = this;
 
+        if (errorLabel != null)
+        {
+            errorLabel.gameObject.SetActive(false);
+        }
+
         ShowTestCases();
     }
 
@@ -35,18 +41,21 @@ public void ShowPurchaseScreen()
     {
         testCasesScreen.SetActive(false);
         purchaseScreen.SetActive(true);
+        ClearError();
         UpdateEntitlements();
     }
 
     public async void PresentPaywall()
     {
+        ClearError();
         try
         {
             await PaywallsPresenter.Present();
         }
         catch (System.Exception e)
         {
             Debug.LogError($"Failed to present paywall: {e}");
+            ShowError(e.Message);
         }
     }
 
@@ -74,4 +83,21 @@ private void UpdateEntitlementsFromInfo(CustomerInfo info)
             entitlementsLabel.text = "Entitlements: " + (hasPro ? "pro" : "none");
         }
     }
+
+    private void ShowError(string message)
+    {
+        if (errorLabel != null)
+        {
+            errorLabel.text = "Error: " + message;
+            errorLabel.gameObject.SetActive(true);
+        }
+    }
+
+    private void ClearError()
+    {
+        if (errorLabel != null)
+        {
+            errorLabel.gameObject.SetActive(false);
+        }
+    }
 }

e2e-tests/MaestroTestApp/setup-instructions.md

@@ -43,6 +43,10 @@ cannot be created outside the editor.
 - Add a child **Button** (UI > Legacy > Button):
   - Set the button's child Text to: `Present Paywall`
   - On Click: drag the Purchases GameObject, select `MaestroTestApp > PresentPaywall`.
+- Add a child **Text** named "ErrorLabel" (UI > Legacy > Text):
+  - Text content: (leave empty)
+  - Font size: 14, color red, centered.
+  - Set it to **inactive** by default.
 - Add a child **Button** for back navigation:
   - Set the button's child Text to: `Back`
   - On Click: drag the Purchases GameObject, select `MaestroTestApp > ShowTestCases`.
@@ -52,6 +56,7 @@ cannot be created outside the editor.
 - Drag "TestCasesScreen" to the `testCasesScreen` field.
 - Drag "PurchaseScreen" to the `purchaseScreen` field.
 - Drag "EntitlementsLabel" Text to the `entitlementsLabel` field.
+- Drag "ErrorLabel" Text to the `errorLabel` field.
 
 ### 6. Project Settings