Make room switches instant and cut redundant client work.

Keep-alive room cache with CSS-only warm switches, nav loading feedback, and per-context members drawer prefs. Share hierarchy/call/sub-room subscriptions, demux state events, and lazy lobby power-level loading to avoid duplicate scans and listener storms.

src/app/state/settings.ts

@@ -36,7 +36,10 @@ export interface Settings {
   pageZoom: number;
   hideActivity: boolean;
 
-  isPeopleDrawer: boolean;
+  /** Last open/closed state of the members panel in non-DM rooms. */
+  peopleDrawerInRooms: boolean;
+  /** Last open/closed state of the members panel in DMs. */
+  peopleDrawerInDirects: boolean;
   isCallPanelDocked: boolean;
   callPanelDockPosition: CallPanelDockPosition;
   memberSortFilterIndex: number;
@@ -79,7 +82,8 @@ const defaultSettings: Settings = {
   pageZoom: 100,
   hideActivity: false,
 
-  isPeopleDrawer: true,
+  peopleDrawerInRooms: true,
+  peopleDrawerInDirects: false,
   isCallPanelDocked: false,
   callPanelDockPosition: 'right',
   memberSortFilterIndex: 0,
@@ -112,15 +116,29 @@ const defaultSettings: Settings = {
 export const getSettings = () => {
   const settings = localStorage.getItem(STORAGE_KEY);
   if (settings === null) return defaultSettings;
-  
-  const parsed = JSON.parse(settings) as Settings & { twitterEmoji?: boolean };
-  
+
+  const parsed = JSON.parse(settings) as Settings & {
+    twitterEmoji?: boolean;
+    isPeopleDrawer?: boolean;
+  };
+
   // Migrate old twitterEmoji boolean to new emojiStyle enum
   if ('twitterEmoji' in parsed && parsed.emojiStyle === undefined) {
     parsed.emojiStyle = parsed.twitterEmoji ? EmojiStyle.Twemoji : EmojiStyle.Apple;
     delete parsed.twitterEmoji;
   }
-  
+
+  // Migrate single people-drawer flag into room/DM prefs.
+  if (
+    typeof parsed.isPeopleDrawer === 'boolean' &&
+    parsed.peopleDrawerInRooms === undefined &&
+    parsed.peopleDrawerInDirects === undefined
+  ) {
+    parsed.peopleDrawerInRooms = parsed.isPeopleDrawer;
+    parsed.peopleDrawerInDirects = parsed.isPeopleDrawer;
+  }
+  delete parsed.isPeopleDrawer;
+
   return {
     ...defaultSettings,
     ...parsed,