fix(desktop): arm mention-first agent prewake

Signed-off-by: Jitter <d14dfe033ef0f809866f9f984de04821b0d900d7652fd85a54776ee40ca3a68f@buzz.block.builderlab.xyz>

desktop/src/features/messages/ui/MessageComposer.tsx

@@ -217,6 +217,7 @@ function MessageComposerImpl({
   const syncAddressedAgentsFromTextRef = React.useRef<(text: string) => void>(
     () => {},
   );
+  const prepareMentionWakeRef = React.useRef<(text: string) => void>(() => {});
   disabledRef.current = disabled;
   isSendingRef.current = isSending;
   isUploadingRef.current = media.isUploading;
@@ -274,6 +275,7 @@ function MessageComposerImpl({
     onUpdate: ({ cursor, linkPreviewContent, text }) => {
       trackAuthoredContent(text);
       contentRef.current = text;
+      prepareMentionWakeRef.current(text);
       setComposerContentFromText(text);
       setPreviewContent(linkPreviewContent);
       if (!isSubmitLockedRef.current && !editTargetRef.current) {
@@ -373,6 +375,7 @@ function MessageComposerImpl({
     restoreQueuedAttachments: media.restoreQueuedAttachments,
     setSpoileredAttachmentUrls,
   });
+  prepareMentionWakeRef.current = mentionSendFlow.prepareMentionWake;
   React.useEffect(() => {
     onDeferredEditPendingChange?.(isDeferredEditPending);
     return () => onDeferredEditPendingChange?.(false);

desktop/src/features/messages/ui/useMentionSendFlow.ts

@@ -116,9 +116,8 @@ export function useMentionSendFlow({
       agents.map((agent) => [normalizePubkey(agent.pubkey), agent]),
     );
   }, [managedAgentsQuery.refetch, queryClient]);
-  useMentionWakePreflight({
+  const { prepareMentionWake } = useMentionWakePreflight({
     channelId,
-    content: contentRef.current,
     contentRef,
     enabled:
       mentionWakeEnabled &&
@@ -984,6 +983,7 @@ export function useMentionSendFlow({
       onInvite: handleInviteNonMembers,
       open: pendingNonMemberSend !== null,
     },
+    prepareMentionWake,
     sendMessageWithMentionFlow,
   };
 }

desktop/src/features/messages/ui/useMentionWakePreflight.test.mjs

@@ -72,6 +72,37 @@ test("wake plan rejects non-member managed agents", () => {
   );
 });
 
+test("editor updates arm a mention-first draft without a rerender", async (t) => {
+  t.mock.timers.enable({ apis: ["setTimeout"] });
+  const { act, renderHook } = await import("@testing-library/react");
+  let starts = 0;
+  const contentRef = { current: "@Fizz " };
+  const view = renderHook(() =>
+    useMentionWakePreflight({
+      channelId: "general",
+      contentRef,
+      enabled: true,
+      expectedRelayUrl: "wss://relay.example",
+      expectedSignerPubkey: "c".repeat(64),
+      getDraftMentionRefs: () => [fizzRef],
+      getManagedAgentsByPubkey: async () =>
+        new Map([[AGENT, { pubkey: AGENT, status: "stopped" }]]),
+      isManagedAgentPubkey: () => true,
+      memberPubkeys: new Set([AGENT]),
+      startManagedAgent: async () => {
+        starts += 1;
+        return { pubkey: AGENT, status: "running" };
+      },
+    }),
+  );
+
+  contentRef.current = "@Fizz please investigate";
+  act(() => view.result.current.prepareMentionWake(contentRef.current));
+  await act(async () => t.mock.timers.tick(MENTION_WAKE_DELAY_MS));
+
+  assert.equal(starts, 1);
+});
+
 test("unmount prevents a wake after an in-flight lookup resolves", async (t) => {
   t.mock.timers.enable({ apis: ["setTimeout"] });
   const { act, renderHook } = await import("@testing-library/react");
@@ -84,7 +115,6 @@ test("unmount prevents a wake after an in-flight lookup resolves", async (t) =>
   const view = renderHook(() =>
     useMentionWakePreflight({
       channelId: "general",
-      content: contentRef.current,
       contentRef,
       enabled: true,
       expectedRelayUrl: "wss://relay.example",

desktop/src/features/messages/ui/useMentionWakePreflight.ts

@@ -68,7 +68,6 @@ export function buildMentionWakePlan({
 
 export function useMentionWakePreflight({
   channelId,
-  content,
   contentRef,
   enabled,
   expectedRelayUrl,
@@ -80,7 +79,6 @@ export function useMentionWakePreflight({
   startManagedAgent,
 }: {
   channelId: string | null;
-  content: string;
   contentRef: React.MutableRefObject<string>;
   enabled: boolean;
   expectedRelayUrl?: string;
@@ -196,10 +194,10 @@ export function useMentionWakePreflight({
 
   // biome-ignore lint/correctness/useExhaustiveDependencies: contextRef keeps callbacks fresh; these inputs are plan invalidation signals.
   React.useEffect(() => {
-    prepareMentionWake(content);
+    prepareMentionWake(contentRef.current);
   }, [
     channelId,
-    content,
+    contentRef,
     enabled,
     expectedRelayUrl,
     expectedSignerPubkey,
@@ -210,4 +208,6 @@ export function useMentionWakePreflight({
   ]);
 
   React.useEffect(() => cancelMentionWake, [cancelMentionWake]);
+
+  return { prepareMentionWake };
 }

desktop/tests/e2e/mentions.spec.ts

@@ -2085,13 +2085,16 @@ test("substantive in-channel managed-agent mentions wake before send", async ({
     "start_managed_agent",
   );
   const input = page.getByTestId("message-input");
-  await input.fill("Hey @fizz");
+  await input.fill("@fizz");
 
   const dropdown = autocomplete(page);
   await expect(dropdown.getByText("fizz")).toBeVisible();
   await expect(dropdown.getByText("agent")).toBeVisible();
   await input.press("Enter");
-  await page.keyboard.type(" can you help?");
+  await page.keyboard.type(
+    " Can you investigate this? Please report what you find.",
+    { delay: 75 },
+  );
 
   await expect
     .poll(