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/pages/client/ClientLayout.tsx

@@ -1,11 +1,18 @@
 import React, { ReactNode } from 'react';
-import { Box } from 'folds';
+import { Box, Line } from 'folds';
+import { useAtom } from 'jotai';
+import { bookmarksPanelAtom } from '../../state/bookmarksPanel';
+import { BookmarksPanel } from '../../features/bookmarks/BookmarksPanel';
+import { ScreenSize, useScreenSizeContext } from '../../hooks/useScreenSize';
 
 type ClientLayoutProps = {
   nav: ReactNode;
   children: ReactNode;
 };
 export function ClientLayout({ nav, children }: ClientLayoutProps) {
+  const [bookmarksOpen, setBookmarksOpen] = useAtom(bookmarksPanelAtom);
+  const screenSize = useScreenSizeContext();
+
   return (
     <>
       <a
@@ -37,6 +44,12 @@ export function ClientLayout({ nav, children }: ClientLayoutProps) {
         <Box grow="Yes" as="main" id="main-content">
           {children}
         </Box>
+        {bookmarksOpen && screenSize === ScreenSize.Desktop && (
+          <>
+            <Line variant="Background" direction="Vertical" size="300" />
+            <BookmarksPanel onClose={() => setBookmarksOpen(false)} />
+          </>
+        )}
       </Box>
     </>
   );