fix(desktop): keep error toasts on screen until dismissed

desktop/src/shared/hooks/useToastEffect.test.mjs

@@ -0,0 +1,19 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+import { feedbackToastOptions } from "./useToastEffect.ts";
+
+test("an error toast is given an explicit close control", () => {
+  assert.equal(feedbackToastOptions("error").closeButton, true);
+});
+
+test("an error toast is not on a timer", () => {
+  const { duration } = feedbackToastOptions("error");
+  // Sonner treats a non-finite duration as "never auto-close"; anything finite
+  // would put a multi-line error back into a race with the reader.
+  assert.equal(Number.isFinite(duration), false);
+});
+
+test("a success toast keeps Sonner's defaults", () => {
+  assert.equal(feedbackToastOptions("success"), undefined);
+});

desktop/src/shared/hooks/useToastEffect.ts

@@ -1,21 +1,36 @@
 import * as React from "react";
 import { toast } from "sonner";
 
+type ToastVariant = "success" | "error";
+
+/**
+ * Errors are the one class of feedback still needed after it is read: they run
+ * to several lines and are often worth copying into a bug report. Sonner's
+ * four-second default races that, so an error stays up until it is dismissed
+ * and carries an explicit close control. A success notice says nothing that
+ * outlives the glance, so it keeps the default treatment.
+ */
+export function feedbackToastOptions(variant: ToastVariant) {
+  return variant === "error"
+    ? { closeButton: true, duration: Number.POSITIVE_INFINITY }
+    : undefined;
+}
+
 /**
  * Show a toast when a message string becomes truthy. Uses a ref to avoid
  * double-firing in React StrictMode (where effects run twice with the same
  * value).
  */
 function useToastEffect(
   message: string | null | undefined,
-  variant: "success" | "error",
+  variant: ToastVariant,
 ) {
   const shownRef = React.useRef<string | null>(null);
 
   React.useEffect(() => {
     if (message && message !== shownRef.current) {
       shownRef.current = message;
-      toast[variant](message);
+      toast[variant](message, feedbackToastOptions(variant));
     }
     if (!message) {
       shownRef.current = null;

desktop/tests/e2e/agents.spec.ts

@@ -2415,11 +2415,18 @@ test("built-in removal failures show up from My Agents", async ({ page }) => {
   await page.getByLabel("Open actions for Honey").click();
   await page.getByRole("menuitem", { name: "Delete" }).click();
 
-  await expect(
-    page
-      .locator("[data-sonner-toast]")
-      .filter({ hasText: "Honey is still referenced by a team." }),
-  ).toBeVisible();
+  const failureToast = page
+    .locator("[data-sonner-toast]")
+    .filter({ hasText: "Honey is still referenced by a team." });
+  await expect(failureToast).toBeVisible();
+
+  // The reported failure: Sonner's four-second default cleared this before a
+  // multi-line error could be read, let alone copied into a report.
+  await page.waitForTimeout(5_000);
+  await expect(failureToast).toBeVisible();
+
+  await failureToast.getByRole("button", { name: "Close toast" }).click();
+  await expect(failureToast).toHaveCount(0);
 });
 
 test("personas referenced by teams cannot be deleted", async ({ page }) => {