fix: ESLint errors and Prettier formatting

ESLint errors:
- usePresenceUpdater: remove redundant `const userId` inside handlePageHide
  that shadowed the outer declaration (no-shadow)
- RoomViewHeader: prefix unused encryptedRoom with _ (no-unused-vars)

Prettier: reformat 14 files to match project style

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

src/app/features/room/RoomViewHeader.tsx

@@ -423,7 +423,7 @@ export function RoomViewHeader({ callView }: { callView?: boolean }) {
 
   const pinnedEvents = useRoomPinnedEvents(room);
   const encryptionEvent = useStateEvent(room, StateEvent.RoomEncryption);
-  const encryptedRoom = !!encryptionEvent;
+  const _encryptedRoom = !!encryptionEvent;
   const avatarMxc = useRoomAvatar(room, direct);
   const name = useLocalRoomName(room);
   const topic = useRoomTopic(room);
@@ -558,7 +558,7 @@ export function RoomViewHeader({ callView }: { callView?: boolean }) {
           </Box>
 
           <Box shrink="No">
-            {(
+            {
               <TooltipProvider
                 position="Bottom"
                 offset={4}
@@ -579,7 +579,7 @@ export function RoomViewHeader({ callView }: { callView?: boolean }) {
                   </IconButton>
                 )}
               </TooltipProvider>
-            )}
+            }
             <TooltipProvider
               position="Bottom"
               offset={4}