refactor: enhance message handling and UI components

- Updated `TeamDetailView` to include `InboxMessage` type and refactored message visibility handling to use a dedicated callback.
- Simplified `ActivityTimeline` by removing unnecessary `useCallback` for message visibility, improving performance.
- Refactored `TaskCommentsSection` to enhance comment expansion logic and improve user interaction with a clearer UI for expanding and collapsing comments.
- Modified `markRead` function to accept an optional full set of messages for better state management and persistence.

src/renderer/components/team/TeamDetailView.tsx

@@ -31,7 +31,7 @@ import { TeamSessionsSection } from './TeamSessionsSection';
 import type { KanbanFilterState } from './kanban/KanbanFilterPopover';
 import type { MessagesFilterState } from './messages/MessagesFilterPopover';
 import type { Session } from '@renderer/types/data';
-import type { ResolvedTeamMember, TeamTask } from '@shared/types';
+import type { InboxMessage, ResolvedTeamMember, TeamTask } from '@shared/types';
 
 interface TeamDetailViewProps {
   teamName: string;
@@ -294,6 +294,10 @@ export const TeamDetailView = ({ teamName }: TeamDetailViewProps): React.JSX.Ele
     () => filteredMessages.filter((m) => !readSet.has(toMessageKey(m))).length,
     [filteredMessages, readSet]
   );
+  const handleMessageVisible = useCallback(
+    (message: InboxMessage) => markRead(toMessageKey(message)),
+    [markRead]
+  );
 
   const kanbanDisplayTasks = useMemo(() => {
     const query = kanbanSearch.trim();
@@ -691,7 +695,7 @@ export const TeamDetailView = ({ teamName }: TeamDetailViewProps): React.JSX.Ele
             setReplyQuote({ from: message.from, text: message.text });
             setSendDialogOpen(true);
           }}
-          onMessageVisible={(message) => markRead(toMessageKey(message))}
+          onMessageVisible={handleMessageVisible}
         />
       </CollapsibleTeamSection>
 

src/renderer/components/team/activity/ActivityTimeline.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useRef } from 'react';
+import { useEffect, useRef } from 'react';
 
 import { getMemberColorByName } from '@shared/constants/memberColors';
 
@@ -39,16 +39,10 @@ const MessageRowWithObserver = ({
 }): React.JSX.Element => {
   const ref = useRef<HTMLDivElement>(null);
   const reportedRef = useRef(false);
-
-  const handleIntersect = useCallback(
-    (entry: IntersectionObserverEntry) => {
-      if (!entry.isIntersecting || !onVisible) return;
-      if (reportedRef.current) return;
-      reportedRef.current = true;
-      onVisible(message);
-    },
-    [message, onVisible]
-  );
+  const messageRef = useRef(message);
+  const onVisibleRef = useRef(onVisible);
+  messageRef.current = message;
+  onVisibleRef.current = onVisible;
 
   useEffect(() => {
     if (!onVisible) return;
@@ -56,13 +50,19 @@ const MessageRowWithObserver = ({
     if (!el) return;
     const observer = new IntersectionObserver(
       ([entry]) => {
-        if (entry) handleIntersect(entry);
+        if (!entry?.isIntersecting) return;
+        if (reportedRef.current) return;
+        const cb = onVisibleRef.current;
+        const msg = messageRef.current;
+        if (!cb) return;
+        reportedRef.current = true;
+        cb(msg);
       },
       { threshold: VIEWPORT_THRESHOLD, rootMargin: '0px' }
     );
     observer.observe(el);
     return () => observer.disconnect();
-  }, [onVisible, handleIntersect]);
+  }, [onVisible]);
 
   return (
     <div ref={ref} className="min-h-px">

src/renderer/components/team/dialogs/TaskCommentsSection.tsx

@@ -116,18 +116,6 @@ export const TaskCommentsSection = ({
                       : formatDistanceToNow(date, { addSuffix: true });
                   })()}
                 </span>
-                <button
-                  type="button"
-                  className="flex items-center gap-0.5 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:text-[var(--color-text-secondary)] group-hover:opacity-100"
-                  onClick={() => toggleCommentExpanded(comment.id)}
-                  title={expandedCommentIds.has(comment.id) ? 'Свернуть' : 'Развернуть'}
-                >
-                  {expandedCommentIds.has(comment.id) ? (
-                    <ChevronUp size={12} />
-                  ) : (
-                    <ChevronDown size={12} />
-                  )}
-                </button>
                 <button
                   type="button"
                   className="ml-auto flex items-center gap-0.5 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:text-[var(--color-text-secondary)] group-hover:opacity-100"
@@ -142,23 +130,68 @@ export const TaskCommentsSection = ({
                   Reply
                 </button>
               </div>
-              <div className="text-xs">
-                {(() => {
-                  const reply = parseMessageReply(comment.text);
-                  const expanded = expandedCommentIds.has(comment.id);
-                  return reply ? (
-                    <ReplyQuoteBlock
-                      reply={reply}
-                      bodyMaxHeight={expanded ? undefined : 'max-h-56'}
-                    />
-                  ) : (
-                    <MarkdownViewer
-                      content={comment.text}
-                      maxHeight={expanded ? undefined : 'max-h-[120px]'}
-                    />
-                  );
-                })()}
-              </div>
+              {(() => {
+                const reply = parseMessageReply(comment.text);
+                const expanded = expandedCommentIds.has(comment.id);
+                const collapsedHeight = 'max-h-[120px]';
+                return (
+                  <div className="relative text-xs">
+                    <div
+                      className={
+                        expanded ? undefined : `relative ${collapsedHeight} overflow-hidden`
+                      }
+                    >
+                      {reply ? (
+                        <ReplyQuoteBlock
+                          reply={reply}
+                          bodyMaxHeight={expanded ? undefined : 'max-h-56'}
+                        />
+                      ) : (
+                        <MarkdownViewer
+                          content={comment.text}
+                          maxHeight={expanded ? undefined : collapsedHeight}
+                        />
+                      )}
+                      {!expanded && (
+                        <>
+                          <div
+                            className="pointer-events-none absolute inset-x-0 bottom-0 h-14"
+                            style={{
+                              background:
+                                'linear-gradient(to top, var(--color-surface) 0%, transparent 100%)',
+                            }}
+                            aria-hidden
+                          />
+                          <div className="absolute inset-x-0 bottom-0 flex justify-center pt-1">
+                            <button
+                              type="button"
+                              className="flex items-center gap-1 rounded-md border border-[var(--color-border)] bg-[var(--color-surface)] px-2.5 py-1 text-[11px] text-[var(--color-text-secondary)] shadow-sm transition-colors hover:bg-[var(--color-surface-raised)] hover:text-[var(--color-text)]"
+                              onClick={() => toggleCommentExpanded(comment.id)}
+                              title="Развернуть"
+                            >
+                              <ChevronDown size={12} />
+                              Развернуть
+                            </button>
+                          </div>
+                        </>
+                      )}
+                    </div>
+                    {expanded && (
+                      <div className="flex justify-center pt-2">
+                        <button
+                          type="button"
+                          className="flex items-center gap-1 rounded-md border border-[var(--color-border)] bg-[var(--color-surface-raised)] px-2.5 py-1 text-[11px] text-[var(--color-text-muted)] transition-colors hover:bg-[var(--color-surface)] hover:text-[var(--color-text-secondary)]"
+                          onClick={() => toggleCommentExpanded(comment.id)}
+                          title="Свернуть"
+                        >
+                          <ChevronUp size={12} />
+                          Свернуть
+                        </button>
+                      </div>
+                    )}
+                  </div>
+                );
+              })()}
             </div>
           ))}
         </div>

src/renderer/hooks/useTeamMessagesRead.ts

@@ -28,7 +28,7 @@ export function useTeamMessagesRead(teamName: string): {
         if (prev.has(messageKey)) return prev;
         const next = new Set(prev);
         next.add(messageKey);
-        markReadStorage(teamName, messageKey);
+        markReadStorage(teamName, messageKey, next);
         return next;
       });
     },

src/renderer/utils/teamMessageReadStorage.ts

@@ -16,12 +16,22 @@ export function getReadSet(teamName: string): Set<string> {
   }
 }
 
-export function markRead(teamName: string, messageKey: string): void {
-  const set = getReadSet(teamName);
-  if (set.has(messageKey)) return;
-  set.add(messageKey);
+/**
+ * Mark a message as read and persist. If `fullSet` is provided, that set is written
+ * (avoids losing keys when a previous write failed). Otherwise reads from localStorage and adds one key.
+ */
+export function markRead(teamName: string, messageKey: string, fullSet?: Set<string>): void {
+  const toWrite =
+    fullSet ??
+    (() => {
+      const set = getReadSet(teamName);
+      if (set.has(messageKey)) return null;
+      set.add(messageKey);
+      return set;
+    })();
+  if (!toWrite) return;
   try {
-    localStorage.setItem(storageKey(teamName), JSON.stringify([...set]));
+    localStorage.setItem(storageKey(teamName), JSON.stringify([...toWrite]));
   } catch {
     // quota or disabled
   }