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/state/bookmarksPanel.ts

@@ -0,0 +1,3 @@
+import { atom } from 'jotai';
+
+export const bookmarksPanelAtom = atom<boolean>(false);

src/app/state/room/roomInputDrafts.ts

@@ -6,10 +6,15 @@ import { IEventRelation } from 'matrix-js-sdk';
 import { createUploadAtomFamily } from '../upload';
 import { TUploadContent } from '../../utils/matrix';
 import { createListAtom } from '../list';
+import { CompressionResult } from '../../utils/imageCompression';
 
 export type TUploadMetadata = {
   markedAsSpoiler: boolean;
   caption?: string;
+  /** User has opted in to compressing this image before upload */
+  compressImage?: boolean;
+  /** Cached compression result (populated in the background when compressImage is set to true) */
+  compressionResult?: CompressionResult | null;
 };
 
 export type TUploadItem = {

src/app/state/roomSettings.ts

@@ -9,6 +9,7 @@ export enum RoomSettingsPage {
   ExportPage,
   ActivityLogPage,
   ServerACLPage,
+  InsightsPage,
 }
 
 export type RoomSettingsState = {

src/app/state/scheduledMessages.ts

@@ -0,0 +1,16 @@
+import { atom } from 'jotai';
+import { IContent } from 'matrix-js-sdk';
+
+export type ScheduledMessage = {
+  delayId: string;
+  roomId: string;
+  content: IContent;
+  sendAt: number; // Unix timestamp ms
+};
+
+/**
+ * Global atom: Map<roomId, ScheduledMessage[]>
+ * Stores all locally-tracked scheduled messages across rooms.
+ * MSC4140 has no list endpoint, so we track them ourselves.
+ */
+export const scheduledMessagesAtom = atom<Map<string, ScheduledMessage[]>>(new Map());