feat: bookmarks, message scheduling, image compression, room insights

P3-1: Message Bookmarks — right-click any message to bookmark; saved to
io.lotus.bookmarks account data (max 500, syncs across devices); star
icon in sidebar opens BookmarksPanel with filter, Jump-to-message, and
remove buttons; reactive to AccountData events

P3-2: Message Scheduling (MSC4140) — clock button next to send opens
ScheduleMessageModal with datetime-local picker; validates ≥1 min future;
calls PUT org.matrix.msc4140 delayed event API; collapsible
ScheduledMessagesTray above composer lists pending messages with cancel;
local Jotai atom tracks scheduled messages per room

P3-3: File Upload Compression — opt-in checkbox per JPEG/PNG file ≥200KB
in upload preview; canvas API compresses at 0.82 quality; shows before/
after size estimate; compressed blob used in upload when checked

P3-7: Room Insights — new Insights tab in room settings; top 5 active
members (bar chart), top 5 reactions (chips), media breakdown (4 tiles),
24-hour activity heatmap (CSS bar chart); all from local cache only with
disclaimer banner; never the first tab shown

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/features/room/message/Message.tsx

@@ -79,6 +79,7 @@ import { PowerIcon } from '../../../components/power';
 import colorMXID from '../../../../util/colorMXID';
 import { getPowerTagIconSrc } from '../../../hooks/useMemberPowerTag';
 import { ForwardMessageDialog } from './ForwardMessageDialog';
+import { useBookmarks } from '../../../hooks/useBookmarks';
 
 // Delivery status indicator for own messages
 function DeliveryStatus({
@@ -792,6 +793,7 @@ export const Message = React.memo(
       const [menuAnchor, setMenuAnchor] = useState<RectCords>();
       const [emojiBoardAnchor, setEmojiBoardAnchor] = useState<RectCords>();
       const [forwardOpen, setForwardOpen] = useState(false);
+      const { addBookmark, removeBookmark, isBookmarked } = useBookmarks();
 
       const senderDisplayName =
         getMemberDisplayName(room, senderId) ?? getMxIdLocalPart(senderId) ?? senderId;
@@ -1128,6 +1130,48 @@ export const Message = React.memo(
                                 </Text>
                               </MenuItem>
                             )}
+                            {!mEvent.isRedacted() && mEvent.getId() && (
+                              <MenuItem
+                                size="300"
+                                after={
+                                  <Icon
+                                    size="100"
+                                    src={Icons.Star}
+                                    filled={isBookmarked(mEvent.getId()!)}
+                                  />
+                                }
+                                radii="300"
+                                onClick={() => {
+                                  const eventId = mEvent.getId()!;
+                                  if (isBookmarked(eventId)) {
+                                    removeBookmark(eventId);
+                                  } else {
+                                    const content = mEvent.getContent();
+                                    const body: string =
+                                      (content?.body as string | undefined) ?? '';
+                                    addBookmark({
+                                      roomId: room.roomId,
+                                      eventId,
+                                      savedAt: Date.now(),
+                                      previewText: body.slice(0, 120),
+                                      roomName: room.name,
+                                    });
+                                  }
+                                  closeMenu();
+                                }}
+                              >
+                                <Text
+                                  className={css.MessageMenuItemText}
+                                  as="span"
+                                  size="T300"
+                                  truncate
+                                >
+                                  {isBookmarked(mEvent.getId()!)
+                                    ? 'Remove Bookmark'
+                                    : 'Bookmark Message'}
+                                </Text>
+                              </MenuItem>
+                            )}
                             {!isThreadedMessage && (
                               <MenuItem
                                 size="300"