Fix task conversation foundation issues

desktop/src/features/agents/agentConversations.test.mjs

@@ -407,3 +407,81 @@ test("continued conversation marker hides same-second messages after the anchor"
 
   assert.deepEqual([...hiddenIds], ["after"]);
 });
+
+test("continued conversation marker with a missing anchor does not hide thread messages", () => {
+  const root = message({
+    body: "Can you look into the data model?",
+    createdAt: 1,
+    id: "root",
+  });
+  const reply = message({
+    body: "One note before opening.",
+    createdAt: 3,
+    id: "reply",
+  });
+  const marker = parseAgentConversationMarker(
+    markerEvent({ content: { agentReplyId: "missing-reply" }, createdAt: 4 }),
+  );
+
+  const hiddenIds = getHiddenAgentConversationMessageIds(
+    [root, reply],
+    marker ? [marker] : [],
+  );
+
+  assert.deepEqual([...hiddenIds], []);
+});
+
+test("continued conversation markers keep later task anchors visible", () => {
+  const root = message({
+    body: "Can you look into the data model?",
+    createdAt: 1,
+    id: "root",
+  });
+  const firstAnchor = message({
+    body: "I'll look into it.",
+    createdAt: 2,
+    id: "agent-reply",
+    pubkey: "agent",
+  });
+  const hiddenReply = message({
+    body: "This should live in the first task.",
+    createdAt: 3,
+    id: "hidden",
+  });
+  const secondAnchor = message({
+    body: "Let's split this into another task.",
+    createdAt: 4,
+    id: "second-anchor",
+    pubkey: "agent",
+  });
+  const laterReply = message({
+    body: "This should also be hidden.",
+    createdAt: 5,
+    id: "later",
+  });
+
+  const firstMarker = parseAgentConversationMarker(
+    markerEvent({ content: { startedAt: 2 }, createdAt: 2 }),
+  );
+  const secondMarker = parseAgentConversationMarker({
+    ...markerEvent({
+      content: { agentReplyId: "second-anchor", startedAt: 4 },
+      createdAt: 4,
+      id: "second-marker",
+    }),
+    tags: [
+      ["h", "channel"],
+      ["e", "root", "", "root"],
+      ["e", "second-anchor", "", "agent-reply"],
+      ["p", "agent"],
+      ["title", "Second task"],
+    ],
+  });
+
+  const hiddenIds = getHiddenAgentConversationMessageIds(
+    [root, firstAnchor, hiddenReply, secondAnchor, laterReply],
+    [firstMarker, secondMarker].filter(Boolean),
+  );
+
+  assert.deepEqual([...hiddenIds], ["hidden", "later"]);
+});

desktop/src/features/agents/agentConversations.ts

@@ -626,26 +626,42 @@ export function getHiddenAgentConversationMessageIds(
   const messageIndexById = new Map(
     orderedMessages.map(({ message }, index) => [message.id, index]),
   );
+  const messageById = new Map(
+    orderedMessages.map(({ message }) => [message.id, message]),
+  );
+  const anchorMessageIdsByThreadRootId = new Map<string, Set<string>>();
   const cutoffByThreadRootId = new Map<
     string,
     {
-      anchorIndex: number | null;
-      anchorMessageId: string;
+      anchorIndex: number;
       startedAt: number;
     }
   >();
   for (const marker of markers) {
+    const anchorMessage = messageById.get(marker.agentReplyId);
+    const anchorIndex = messageIndexById.get(marker.agentReplyId);
+    if (!anchorMessage || anchorIndex === undefined) {
+      continue;
+    }
+
+    const anchorThreadRootId =
+      anchorMessage.rootId ?? anchorMessage.parentId ?? anchorMessage.id;
+    if (anchorThreadRootId !== marker.threadRootId) {
+      continue;
+    }
+
+    const anchorMessageIds =
+      anchorMessageIdsByThreadRootId.get(marker.threadRootId) ?? new Set();
+    anchorMessageIds.add(marker.agentReplyId);
+    anchorMessageIdsByThreadRootId.set(marker.threadRootId, anchorMessageIds);
+
     const current = cutoffByThreadRootId.get(marker.threadRootId);
     const candidate = {
-      anchorIndex: messageIndexById.get(marker.agentReplyId) ?? null,
-      anchorMessageId: marker.agentReplyId,
+      anchorIndex,
       startedAt: marker.startedAt,
     };
     const isEarlier =
-      current === undefined ||
-      (candidate.anchorIndex !== null && current.anchorIndex !== null
-        ? candidate.anchorIndex < current.anchorIndex
-        : candidate.startedAt < current.startedAt);
+      current === undefined || candidate.anchorIndex < current.anchorIndex;
     if (isEarlier) {
       cutoffByThreadRootId.set(marker.threadRootId, candidate);
     }
@@ -659,12 +675,15 @@ export function getHiddenAgentConversationMessageIds(
     }
 
     const cutoff = cutoffByThreadRootId.get(threadRootId);
-    if (cutoff === undefined || message.id === cutoff.anchorMessageId) {
+    if (
+      cutoff === undefined ||
+      anchorMessageIdsByThreadRootId.get(threadRootId)?.has(message.id)
+    ) {
       continue;
     }
 
     const messageIndex = messageIndexById.get(message.id);
-    if (cutoff.anchorIndex !== null && messageIndex !== undefined) {
+    if (messageIndex !== undefined) {
       if (messageIndex > cutoff.anchorIndex) {
         hiddenIds.add(message.id);
       }

desktop/src/features/channels/ui/ChannelPane.tsx

@@ -242,17 +242,6 @@ export const ChannelPane = React.memo(function ChannelPane({
     return true;
   }, [findLastOwnEditable, messages, onEdit]);
 
-  const handleEditLastOwnThreadMessage = React.useCallback((): boolean => {
-    if (!onEdit) return false;
-    const scope: TimelineMessage[] = [];
-    if (threadHeadMessage) scope.push(threadHeadMessage);
-    for (const entry of threadMessages) scope.push(entry.message);
-    const target = findLastOwnEditable(scope);
-    if (!target) return false;
-    onEdit(target);
-    return true;
-  }, [findLastOwnEditable, onEdit, threadHeadMessage, threadMessages]);
-
   const isComposerDisabled =
     !activeChannel?.isMember ||
     activeChannel.archivedAt !== null ||

desktop/src/features/messages/lib/timelineItems.test.mjs

@@ -86,6 +86,24 @@ test("buildTimelineItems: system messages flatten to a 'system' item", () => {
   assert.deepEqual(kinds(items), ["day-divider", "message", "system"]);
 });
 
+test("buildTimelineItems: can omit only the initial day divider", () => {
+  const entries = [
+    entry({ id: "d1a", createdAt: dayAt(2026, 6, 13) }),
+    entry({ id: "d1b", createdAt: dayAt(2026, 6, 13, 13) }),
+    entry({ id: "d2a", createdAt: dayAt(2026, 6, 14) }),
+  ];
+  const { items } = buildTimelineItems(entries, null, {
+    showInitialDayDivider: false,
+  });
+
+  assert.deepEqual(kinds(items), [
+    "message",
+    "message",
+    "day-divider",
+    "message",
+  ]);
+});
+
 test("buildTimelineItems: empty entries produce no items", () => {
   const { items } = buildTimelineItems([], null);
   assert.equal(items.length, 0);

desktop/src/features/messages/lib/timelineItems.ts

@@ -30,6 +30,10 @@ export type TimelineItemsResult = {
   items: TimelineItem[];
 };
 
+type BuildTimelineItemsOptions = {
+  showInitialDayDivider?: boolean;
+};
+
 /** Stable per-item key, unique across the flattened stream. */
 export function getTimelineItemKey(item: TimelineItem): string {
   return item.key;
@@ -47,6 +51,7 @@ function entryRenderKey(entry: MainTimelineEntry): string {
 export function buildTimelineItems(
   entries: MainTimelineEntry[],
   firstUnreadMessageId: string | null,
+  { showInitialDayDivider = true }: BuildTimelineItemsOptions = {},
 ): TimelineItemsResult {
   const items: TimelineItem[] = [];
 
@@ -66,7 +71,7 @@ export function buildTimelineItems(
     const renderKey = entryRenderKey(entry);
 
     const dayBoundary = dayBoundariesByStartIndex.get(i);
-    if (dayBoundary) {
+    if (dayBoundary && (showInitialDayDivider || i !== 0)) {
       items.push({
         kind: "day-divider",
         key: dayBoundary.key,

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

@@ -94,6 +94,7 @@ type MessageTimelineProps = {
   searchMatchingMessageIds?: Set<string>;
   /** The current find-in-channel query string. */
   searchQuery?: string;
+  showInitialDayDivider?: boolean;
   targetMessageId?: string | null;
   onTargetReached?: (messageId: string) => void;
   /** Event id of the oldest unread top-level message at channel open, or null. */
@@ -189,6 +190,7 @@ const MessageTimelineBase = React.forwardRef<
     searchActiveMessageId = null,
     searchMatchingMessageIds,
     searchQuery,
+    showInitialDayDivider = true,
     targetMessageId = null,
     onTargetReached,
     firstUnreadMessageId = null,
@@ -239,7 +241,7 @@ const MessageTimelineBase = React.forwardRef<
   // scrollTop into the current scroll element during navigation; reusing the
   // same node across channel routes can leave the newly-loaded message list
   // painted at a stale offset until the user's next scroll event forces layout.
-  const scrollContainerDomKey = channelId ?? "none";
+  const scrollContainerDomKey = `${channelId ?? "none"}:${layoutShiftKey ?? "none"}`;
 
   const timelineBodySurface = selectTimelineBodySurface({
     deferredCount: deferredMessages.length,
@@ -634,6 +636,7 @@ const MessageTimelineBase = React.forwardRef<
                     searchActiveMessageId={searchActiveMessageId}
                     searchMatchingMessageIds={searchMatchingMessageIds}
                     searchQuery={searchQuery}
+                    showInitialDayDivider={showInitialDayDivider}
                     threadUnreadCounts={threadUnreadCounts}
                     unfollowThreadById={unfollowThreadById}
                   />

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

@@ -78,6 +78,7 @@ type TimelineMessageListProps = {
   searchMatchingMessageIds?: Set<string>;
   /** The current find-in-channel query string. */
   searchQuery?: string;
+  showInitialDayDivider?: boolean;
   /** Per-thread unread counts keyed by thread root id. */
   threadUnreadCounts?: ReadonlyMap<string, number>;
 };
@@ -112,6 +113,7 @@ export const TimelineMessageList = React.memo(function TimelineMessageList({
   searchActiveMessageId = null,
   searchMatchingMessageIds,
   searchQuery,
+  showInitialDayDivider = true,
   threadUnreadCounts,
   unfollowThreadById,
 }: TimelineMessageListProps) {
@@ -168,8 +170,11 @@ export const TimelineMessageList = React.memo(function TimelineMessageList({
   // The flattened item stream, memoized on the entries and the unread boundary
   // (the unread divider is its own item, so it shifts subsequent rows).
   const itemsResult = React.useMemo(
-    () => buildTimelineItems(entries, firstUnreadMessageId),
-    [entries, firstUnreadMessageId],
+    () =>
+      buildTimelineItems(entries, firstUnreadMessageId, {
+        showInitialDayDivider,
+      }),
+    [entries, firstUnreadMessageId, showInitialDayDivider],
   );
   const agentConversationMarkerByMessageId = React.useMemo(
     () =>

desktop/src/features/sidebar/ui/AppSidebar.tsx

@@ -493,45 +493,8 @@ export function AppSidebar({
     return byChannelId;
   }, [agentConversations]);
   const isAgentConversationActive = selectedView === "agents";
-  const activeAgentConversationChannelId = React.useMemo(() => {
-    if (!isAgentConversationActive || !selectedAgentConversationId) {
-      return null;
-    }
-
-    return (
-      agentConversations.find(
-        (conversation) => conversation.id === selectedAgentConversationId,
-      )?.channelId ?? null
-    );
-  }, [
-    agentConversations,
-    isAgentConversationActive,
-    selectedAgentConversationId,
-  ]);
-  const displayUnreadChannelIds = React.useMemo(() => {
-    if (
-      !activeAgentConversationChannelId ||
-      !unreadChannelIds.has(activeAgentConversationChannelId)
-    ) {
-      return unreadChannelIds;
-    }
-
-    const next = new Set(unreadChannelIds);
-    next.delete(activeAgentConversationChannelId);
-    return next;
-  }, [activeAgentConversationChannelId, unreadChannelIds]);
-  const displayUnreadChannelCounts = React.useMemo(() => {
-    if (
-      !activeAgentConversationChannelId ||
-      !unreadChannelCounts.has(activeAgentConversationChannelId)
-    ) {
-      return unreadChannelCounts;
-    }
-
-    const next = new Map(unreadChannelCounts);
-    next.delete(activeAgentConversationChannelId);
-    return next;
-  }, [activeAgentConversationChannelId, unreadChannelCounts]);
+  const displayUnreadChannelIds = unreadChannelIds;
+  const displayUnreadChannelCounts = unreadChannelCounts;
   const sidebarLoadingShape = useSidebarLoadingShape({
     activeWorkspaceId: activeWorkspace?.id,
     currentPubkey,