fix: avatar decoration centering, animation flickering, scheduled message persistence

- UserHero: move AvatarDecoration inside AvatarPresence so the decoration
  inline-flex container sizes to the avatar only, not the presence badge
- SidebarNav: add will-change: background-position, background-size on
  document.body for animated backgrounds, promoting them to a compositor
  layer so overlaid text/UI doesn't repaint on every animation frame
- scheduledMessages: back the atom with atomWithStorage so the scheduled
  message tray survives page refreshes via localStorage

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

src/app/components/user-profile/UserHero.tsx

@@ -49,12 +49,12 @@ export function UserHero({ userId, avatarUrl, presence }: UserHeroProps) {
       </div>
       <div className={css.UserHeroAvatarContainer}>
         <div className={css.UserAvatarContainer}>
-          <AvatarDecoration userId={userId} inset={20}>
-            <AvatarPresence
-              badge={
-                presence && <PresenceBadge presence={presence.presence} status={presence.status} />
-              }
-            >
+          <AvatarPresence
+            badge={
+              presence && <PresenceBadge presence={presence.presence} status={presence.status} />
+            }
+          >
+            <AvatarDecoration userId={userId} inset={20}>
               <Avatar
                 as={avatarUrl ? 'button' : 'div'}
                 onClick={avatarUrl ? () => setViewAvatar(avatarUrl) : undefined}
@@ -69,8 +69,8 @@ export function UserHero({ userId, avatarUrl, presence }: UserHeroProps) {
                   renderFallback={() => <Icon size="500" src={Icons.User} filled />}
                 />
               </Avatar>
-            </AvatarPresence>
-          </AvatarDecoration>
+            </AvatarDecoration>
+          </AvatarPresence>
         </div>
         {viewAvatar && (
           <Overlay open backdrop={<OverlayBackdrop />}>

src/app/pages/client/SidebarNav.tsx

@@ -48,6 +48,7 @@ export function SidebarNav() {
       style.removeProperty('background-size');
       style.removeProperty('background-position');
       style.removeProperty('animation');
+      style.removeProperty('will-change');
       return;
     }
 
@@ -58,6 +59,13 @@ export function SidebarNav() {
     style.backgroundSize = (bgStyle.backgroundSize as string | undefined) ?? '';
     style.backgroundPosition = (bgStyle.backgroundPosition as string | undefined) ?? '';
     style.animation = (bgStyle.animation as string | undefined) ?? '';
+    // Promote animated backgrounds to their own compositor layer so the browser
+    // doesn't repaint the overlaid text/UI content on every animation frame.
+    if (bgStyle.animation) {
+      style.willChange = 'background-position, background-size';
+    } else {
+      style.removeProperty('will-change');
+    }
 
     return () => {
       style.removeProperty('background-image');
@@ -65,6 +73,7 @@ export function SidebarNav() {
       style.removeProperty('background-size');
       style.removeProperty('background-position');
       style.removeProperty('animation');
+      style.removeProperty('will-change');
     };
   }, [glassmorphismSidebar, chatBackground, lotusTerminal, isDark, pauseAnimations]);
 

src/app/state/scheduledMessages.ts

@@ -1,4 +1,5 @@
 import { atom } from 'jotai';
+import { atomWithStorage, createJSONStorage } from 'jotai/utils';
 import { IContent } from 'matrix-js-sdk';
 
 export type ScheduledMessage = {
@@ -8,9 +9,34 @@ export type ScheduledMessage = {
   sendAt: number; // Unix timestamp ms
 };
 
+const STORAGE_KEY = 'cinny_scheduled_messages_v1';
+
+// Internal atom persists as a plain Record (JSON-serializable).
+const internalAtom = atomWithStorage<Record<string, ScheduledMessage[]>>(
+  STORAGE_KEY,
+  {},
+  createJSONStorage(() => localStorage),
+);
+
 /**
  * Global atom: Map<roomId, ScheduledMessage[]>
  * Stores all locally-tracked scheduled messages across rooms.
  * MSC4140 has no list endpoint, so we track them ourselves.
+ * Backed by localStorage so scheduled messages survive page refreshes.
  */
-export const scheduledMessagesAtom = atom<Map<string, ScheduledMessage[]>>(new Map());
+export const scheduledMessagesAtom = atom(
+  (get): Map<string, ScheduledMessage[]> => new Map(Object.entries(get(internalAtom))),
+  (
+    _get,
+    set,
+    updater:
+      | Map<string, ScheduledMessage[]>
+      | ((prev: Map<string, ScheduledMessage[]>) => Map<string, ScheduledMessage[]>),
+  ) => {
+    set(internalAtom, (prevObj) => {
+      const prevMap = new Map(Object.entries(prevObj));
+      const nextMap = typeof updater === 'function' ? updater(prevMap) : updater;
+      return Object.fromEntries(nextMap.entries());
+    });
+  },
+);