fix(chat): delay delivery warning and shorten queued action label

Wait one second before displaying pending-input recovery UI, cancelling on confirmation or removal. Label the queued-message stop action Flush without changing behavior. Verified: 2451 frontend tests passed twice, typecheck, Biome, and build.

7 files changed, 280 insertions, 34 deletions

diff --git a/src/app/App.test.ts b/src/app/App.test.ts
index 42d30ed..9c5f5cc 100644
--- a/src/app/App.test.ts
+++ b/src/app/App.test.ts
@@ -482,7 +482,7 @@ describe("App component interaction tests", () => {
     store.dispose();
   });
 
-  it("uses only the focused conversation's queue snapshot for the interrupt label and POSTs stop", async () => {
+  it("uses only the focused conversation's queue snapshot for the Flush label and POSTs stop", async () => {
     const ws = fakeSocket();
     const fetchImpl = vi.fn(fakeFetchImpl());
     const store = createAppStore({
@@ -523,10 +523,10 @@ describe("App component interaction tests", () => {
     });
     const pending = { messages: [{ id: "m1", text: "next", queuedAt: 1 }] };
     pushQueue(firstId, pending);
-    const interrupt = await screen.findByRole("button", { name: "Interrupt & send queued" });
+    const flush = await screen.findByRole("button", { name: "Flush" });
     ws.sent.length = 0;
     fetchImpl.mockClear();
-    await user.click(interrupt);
+    await user.click(flush);
     expect(fetchImpl.mock.calls.filter(([, init]) => init?.method === "POST")).toEqual([
       [expect.stringContaining(`/conversations/${firstId}/stop`), { method: "POST" }],
     ]);
@@ -544,7 +544,7 @@ describe("App component interaction tests", () => {
       expect(screen.getByRole("button", { name: "Stop generation" })).toBeInTheDocument(),
     );
     pushQueue(secondId, pending);
-    await screen.findByRole("button", { name: "Interrupt & send queued" });
+    await screen.findByRole("button", { name: "Flush" });
     pushQueue(secondId, { messages: [] });
     await screen.findByRole("button", { name: "Stop generation" });
     pushQueue(secondId, { messages: "malformed" });
diff --git a/src/features/chat/logic/composer.test.ts b/src/features/chat/logic/composer.test.ts
index 6ef5eab..86e9dc4 100644
--- a/src/features/chat/logic/composer.test.ts
+++ b/src/features/chat/logic/composer.test.ts
@@ -10,10 +10,10 @@ describe("stopButtonLabels", () => {
     });
   });
 
-  it.each([1, 2])("describes interrupt-and-send with queued count %s", (count) => {
+  it.each([1, 2])("labels the queued Stop action Flush with queued count %s", (count) => {
     expect(stopButtonLabels(count)).toEqual({
-      text: "Interrupt & send queued",
-      ariaLabel: "Interrupt & send queued",
+      text: "Flush",
+      ariaLabel: "Flush",
       title: "Stop the current response and start the queued message now",
     });
   });
diff --git a/src/features/chat/logic/composer.ts b/src/features/chat/logic/composer.ts
index 1ea8173..e56a007 100644
--- a/src/features/chat/logic/composer.ts
+++ b/src/features/chat/logic/composer.ts
@@ -2,8 +2,8 @@
 export function stopButtonLabels(queuedMessageCount: number | undefined) {
   if (queuedMessageCount !== undefined && queuedMessageCount >= 1) {
     return {
-      text: "Interrupt & send queued",
-      ariaLabel: "Interrupt & send queued",
+      text: "Flush",
+      ariaLabel: "Flush",
       title: "Stop the current response and start the queued message now",
     };
   }
diff --git a/src/features/chat/ui.test.ts b/src/features/chat/ui.test.ts
index 480d593..74c0619 100644
--- a/src/features/chat/ui.test.ts
+++ b/src/features/chat/ui.test.ts
@@ -871,14 +871,14 @@ describe("Composer", () => {
 
     for (const queuedMessageCount of [1, 2]) {
       await rerender({ queuedMessageCount });
-      const button = screen.getByRole("button", { name: "Interrupt & send queued" });
-      expect(button).toHaveTextContent(/^Interrupt & send queued$/);
+      const button = screen.getByRole("button", { name: "Flush" });
+      expect(button).toHaveTextContent(/^Flush$/);
       expect(button).toHaveAttribute(
         "title",
         "Stop the current response and start the queued message now",
       );
     }
-    await user.click(screen.getByRole("button", { name: "Interrupt & send queued" }));
+    await user.click(screen.getByRole("button", { name: "Flush" }));
     expect(onStop).toHaveBeenCalledTimes(2);
     expect(onSend).not.toHaveBeenCalled();
     expect(onQueue).not.toHaveBeenCalled();
@@ -886,10 +886,10 @@ describe("Composer", () => {
     const input = screen.getByRole("textbox", { name: "Message input" });
     await user.type(input, "next");
     expect(screen.getByRole("button", { name: "Queue" })).toBeInTheDocument();
-    expect(screen.queryByRole("button", { name: "Interrupt & send queued" })).toBeNull();
+    expect(screen.queryByRole("button", { name: "Flush" })).toBeNull();
     await user.click(screen.getByRole("button", { name: "Queue" }));
     expect(onQueue).toHaveBeenCalledExactlyOnceWith("next", undefined);
-    expect(screen.getByRole("button", { name: "Interrupt & send queued" })).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Flush" })).toBeInTheDocument();
     await rerender({ queuedMessageCount: 0 });
     expectPlainStop(); // Queue drained or cancelled.
     await rerender({ queuedMessageCount: 1, status: "idle" });
diff --git a/src/features/chat/ui/PendingInputWarning.svelte b/src/features/chat/ui/PendingInputWarning.svelte
new file mode 100644
index 0000000..c9e675e
--- /dev/null
+++ b/src/features/chat/ui/PendingInputWarning.svelte
@@ -0,0 +1,47 @@
+<script lang="ts">
+  import { onMount } from "svelte";
+  import type { PendingInput } from "../pending-inputs";
+
+  let {
+    input,
+    onDiscard,
+  }: {
+    input: PendingInput;
+    onDiscard: (requestId: string) => void;
+  } = $props();
+
+  let visible = $state(false);
+
+  // Presentation only: each keyed row gets one grace period, including restored
+  // or rejected inputs. Prop updates never restart it. Confirmation/discard
+  // removes the row, cancelling the timer along with any other unmount.
+  onMount(() => {
+    const timer = setTimeout(() => {
+      visible = true;
+    }, 1000);
+    return () => clearTimeout(timer);
+  });
+</script>
+
+{#if visible}
+  <div class="m-3 rounded border border-warning p-3 text-sm" role="status">
+    <p>
+      {input.rejection
+        ? `Message rejected: ${input.rejection}`
+        : "Delivery unconfirmed. Your input is saved on this device."}
+    </p>
+    <p>Check the conversation history before sending again to avoid a duplicate.</p>
+    <textarea
+      class="textarea textarea-bordered mt-2 w-full"
+      aria-label="Saved message"
+      readonly
+      value={input.request.type === "chat.send" ? input.request.message : input.request.text}
+    ></textarea>
+    {#each input.request.images ?? [] as image}
+      <img class="my-2 max-h-32" src={image.url} alt="Saved attachment" />
+    {/each}
+    <button class="btn btn-sm mt-2" onclick={() => onDiscard(input.request.requestId)}
+      >Discard saved copy</button
+    >
+  </div>
+{/if}
diff --git a/src/features/chat/ui/PendingInputs.svelte b/src/features/chat/ui/PendingInputs.svelte
index cbaf35f..dcb7aee 100644
--- a/src/features/chat/ui/PendingInputs.svelte
+++ b/src/features/chat/ui/PendingInputs.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
   import type { PendingInput } from "../pending-inputs";
+  import PendingInputWarning from "./PendingInputWarning.svelte";
 
   let {
     inputs,
@@ -11,24 +12,5 @@
 </script>
 
 {#each inputs as input (input.request.requestId)}
-  <div class="m-3 rounded border border-warning p-3 text-sm" role="status">
-    <p>
-      {input.rejection
-        ? `Message rejected: ${input.rejection}`
-        : "Delivery unconfirmed. Your input is saved on this device."}
-    </p>
-    <p>Check the conversation history before sending again to avoid a duplicate.</p>
-    <textarea
-      class="textarea textarea-bordered mt-2 w-full"
-      aria-label="Saved message"
-      readonly
-      value={input.request.type === "chat.send" ? input.request.message : input.request.text}
-    ></textarea>
-    {#each input.request.images ?? [] as image}
-      <img class="my-2 max-h-32" src={image.url} alt="Saved attachment" />
-    {/each}
-    <button class="btn btn-sm mt-2" onclick={() => onDiscard(input.request.requestId)}
-      >Discard saved copy</button
-    >
-  </div>
+  <PendingInputWarning {input} {onDiscard} />
 {/each}
diff --git a/src/features/chat/ui/PendingInputs.test.ts b/src/features/chat/ui/PendingInputs.test.ts
new file mode 100644
index 0000000..cea770d
--- /dev/null
+++ b/src/features/chat/ui/PendingInputs.test.ts
@@ -0,0 +1,217 @@
+import { cleanup, fireEvent, render, screen } from "@testing-library/svelte";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import type { PendingInput } from "../pending-inputs";
+import { createChatStore } from "../store.svelte";
+import {
+  createFakeCache,
+  createFakeHistorySync,
+  createFakeMetricsSync,
+  createFakeTransport,
+} from "../test-helpers";
+import PendingInputs from "./PendingInputs.svelte";
+
+function input(requestId: string, type: "chat.send" | "chat.queue" = "chat.send"): PendingInput {
+  return {
+    request: {
+      ...(type === "chat.send" ? { type, message: requestId } : { type, text: requestId }),
+      conversationId: "c",
+      requestId,
+      images: [{ url: "data:image/png;base64,AAAA", mimeType: "image/png" }],
+    },
+  };
+}
+
+beforeEach(() => vi.useFakeTimers());
+afterEach(() => {
+  cleanup();
+  const remaining = vi.getTimerCount();
+  vi.useRealTimers();
+  expect(remaining).toBe(0);
+});
+
+describe("pending input warning grace period", () => {
+  it.each([
+    "chat.send",
+    "chat.queue",
+  ] as const)("renders no %s recovery UI before 1000 ms, then keeps its content stable", async (type) => {
+    const { container } = render(PendingInputs, {
+      inputs: [input("saved message", type)],
+      onDiscard: vi.fn(),
+    });
+    expect(container.children).toHaveLength(0);
+    expect(container.textContent).toBe("");
+    await vi.advanceTimersByTimeAsync(999);
+    expect(container.children).toHaveLength(0);
+    expect(container.textContent).toBe("");
+    expect(screen.queryByRole("status")).toBeNull();
+    await vi.advanceTimersByTimeAsync(1);
+    const warning = screen.getByRole("status");
+    expect(warning).toHaveTextContent("Delivery unconfirmed. Your input is saved on this device.");
+    expect(warning).toHaveTextContent(
+      "Check the conversation history before sending again to avoid a duplicate.",
+    );
+    expect(screen.getByRole("textbox", { name: "Saved message" })).toHaveValue("saved message");
+    expect(screen.getByRole("img", { name: "Saved attachment" })).toHaveAttribute(
+      "src",
+      "data:image/png;base64,AAAA",
+    );
+    const content = warning.innerHTML;
+    await vi.advanceTimersByTimeAsync(10_000);
+    expect(screen.getByRole("status")).toBe(warning);
+    expect(warning.innerHTML).toBe(content);
+  });
+
+  it.each([
+    "confirmation",
+    "discard",
+  ])("%s before the threshold cancels the timer and never flashes later", async (resolution) => {
+    const transport = createFakeTransport();
+    const save = vi.fn();
+    const store = createChatStore({
+      conversationId: "c",
+      createRequestId: () => "first",
+      transport: transport.impl,
+      historySync: createFakeHistorySync().impl,
+      metricsSync: createFakeMetricsSync().impl,
+      cache: createFakeCache().impl,
+      pendingInputStorage: { load: () => [], save },
+    });
+    try {
+      store.send("first");
+      // Saving and transmission stay immediate, independent of warning display.
+      expect(save).toHaveBeenCalledExactlyOnceWith(store.pendingInputs);
+      expect(transport.sent).toHaveLength(1);
+      const { container, rerender } = render(PendingInputs, {
+        inputs: store.pendingInputs,
+        onDiscard: store.discardPendingInput,
+      });
+      await vi.advanceTimersByTimeAsync(999);
+      if (resolution === "confirmation") {
+        store.handleDelta({ type: "chat.accepted", conversationId: "c", requestId: "first" });
+      } else {
+        store.discardPendingInput("first");
+      }
+      expect(store.pendingInputs).toEqual([]);
+      expect(save).toHaveBeenLastCalledWith([]);
+      await rerender({ inputs: store.pendingInputs });
+      expect(vi.getTimerCount()).toBe(0);
+      expect(container.children).toHaveLength(0);
+      expect(container.textContent).toBe("");
+      await vi.advanceTimersByTimeAsync(10_000);
+      expect(container.children).toHaveLength(0);
+      expect(container.textContent).toBe("");
+    } finally {
+      store.dispose();
+    }
+  });
+
+  it("hides an already visible warning immediately on confirmation", async () => {
+    const { container, rerender } = render(PendingInputs, {
+      inputs: [input("first")],
+      onDiscard: vi.fn(),
+    });
+    await vi.advanceTimersByTimeAsync(1000);
+    expect(screen.getByRole("status")).toBeInTheDocument();
+    await rerender({ inputs: [] });
+    expect(container.children).toHaveLength(0);
+    expect(container.textContent).toBe("");
+  });
+
+  it("preserves the discard action and hides the saved copy without another delay", async () => {
+    const onDiscard = vi.fn();
+    const { container, rerender } = render(PendingInputs, {
+      inputs: [input("first")],
+      onDiscard,
+    });
+    await vi.advanceTimersByTimeAsync(1000);
+    await fireEvent.click(screen.getByRole("button", { name: "Discard saved copy" }));
+    expect(onDiscard).toHaveBeenCalledExactlyOnceWith("first");
+    await rerender({ inputs: [] });
+    expect(container.children).toHaveLength(0);
+    expect(container.textContent).toBe("");
+  });
+
+  it("cancels all waiting timers on unmount", async () => {
+    const { unmount } = render(PendingInputs, {
+      inputs: [input("first"), input("second")],
+      onDiscard: vi.fn(),
+    });
+    expect(vi.getTimerCount()).toBe(2);
+    await vi.advanceTimersByTimeAsync(500);
+    unmount();
+    expect(vi.getTimerCount()).toBe(0);
+    await vi.advanceTimersByTimeAsync(10_000);
+    expect(screen.queryByRole("status")).toBeNull();
+  });
+
+  it("gives successive inputs independent delays without restarting existing rows", async () => {
+    const first = input("first");
+    const second = input("second");
+    const { rerender } = render(PendingInputs, { inputs: [first], onDiscard: vi.fn() });
+    await vi.advanceTimersByTimeAsync(600);
+    await rerender({ inputs: [second, { ...first }], onDiscard: vi.fn() });
+    await vi.advanceTimersByTimeAsync(399);
+    expect(screen.queryByRole("status")).toBeNull();
+    await vi.advanceTimersByTimeAsync(1);
+    const warning = screen.getByRole("status");
+    expect(screen.getByRole("textbox")).toHaveValue("first");
+    await rerender({ inputs: [{ ...second }, { ...first }], onDiscard: vi.fn() });
+    await vi.advanceTimersByTimeAsync(599);
+    expect(screen.getAllByRole("status")).toEqual([warning]);
+    await vi.advanceTimersByTimeAsync(1);
+    expect(
+      screen.getAllByRole("textbox").map((node) => (node as HTMLTextAreaElement).value),
+    ).toEqual(["second", "first"]);
+    // Removing the older warning must not re-hide/restart the newer warning.
+    await rerender({ inputs: [second] });
+    expect(screen.getByRole("textbox")).toHaveValue("second");
+    expect(vi.getTimerCount()).toBe(0);
+  });
+
+  it("starts a fresh delay after an earlier input was confirmed during its grace period", async () => {
+    const { rerender } = render(PendingInputs, { inputs: [input("first")], onDiscard: vi.fn() });
+    await vi.advanceTimersByTimeAsync(600);
+    await rerender({ inputs: [] });
+    await rerender({ inputs: [input("second")] });
+    await vi.advanceTimersByTimeAsync(999);
+    expect(screen.queryByRole("status")).toBeNull();
+    await vi.advanceTimersByTimeAsync(1);
+    expect(screen.getByRole("textbox")).toHaveValue("second");
+  });
+
+  it("keeps the original deadline when rejection arrives, and updates visible content immediately", async () => {
+    const pending = input("first");
+    const { rerender } = render(PendingInputs, { inputs: [pending], onDiscard: vi.fn() });
+    await vi.advanceTimersByTimeAsync(600);
+    await rerender({ inputs: [{ ...pending, rejection: "disk full" }] });
+    await vi.advanceTimersByTimeAsync(399);
+    expect(screen.queryByRole("status")).toBeNull();
+    await vi.advanceTimersByTimeAsync(1);
+    const warning = screen.getByRole("status");
+    expect(warning).toHaveTextContent("Message rejected: disk full");
+    expect(warning).not.toHaveTextContent("Delivery unconfirmed");
+    await rerender({ inputs: [{ ...pending, rejection: "still rejected" }] });
+    expect(screen.getByRole("status")).toBe(warning);
+    expect(warning).toHaveTextContent("Message rejected: still rejected");
+    expect(vi.getTimerCount()).toBe(0);
+  });
+
+  it.each([
+    undefined,
+    "disk full",
+  ])("restored entries (rejection: %s) use the same grace period and retain recovery content", async (rejection) => {
+    const restored = input("restored saved message");
+    render(PendingInputs, {
+      inputs: [rejection === undefined ? restored : { ...restored, rejection }],
+      onDiscard: vi.fn(),
+    });
+    await vi.advanceTimersByTimeAsync(999);
+    expect(screen.queryByRole("status")).toBeNull();
+    await vi.advanceTimersByTimeAsync(1);
+    expect(screen.getByRole("status")).toHaveTextContent(
+      rejection === undefined ? "Delivery unconfirmed" : "Message rejected: disk full",
+    );
+    expect(screen.getByRole("textbox")).toHaveValue("restored saved message");
+    expect(screen.getByRole("button", { name: "Discard saved copy" })).toBeEnabled();
+  });
+});